Bhagavad Gita, chapter 18, verse 51

Adjectives in Sanskrit may be grouped under three heads.

• Adjectives derived from the substantives like mānuṣa (human), sukhin(one who is happy) etc.
• Simple adjectives like śubha (shining), sundar (beautiful), priya (dear)etc.
• Compound adjectives formed by using roots and substantives at the end of the compounds like durbuddhi (evil-mind), marmaspṛś (that which touches any sensitive part of the body or psyche) vedavid ( the knower of the Vedas) etc.

All these follow the number and gender of the nouns they qualify and are inflected precisely like noun-stems.

There are eight cases in Sanskrit for the inflection of nouns, pronouns, adjectives and substantives. They are: Nominative (the first), Accusative (the second), Instrumental (the third), Dative (the fourth), Ablative (the fifth), Genitive (the sixth), Locative (the seventh), and Vocative (the eighth).

The Nominative is the case of the subject of the sentence, and of any word qualifying the subject, whether attributively, in apposition, or as a predicate. For example: bālakaḥ paṭhati' The boy is reading'.

The Accusative is especially the case of the direct object of a transitive verb, and of any word qualifying that object, as attribute, appositive or objective predicate. For example: bālakaṁ paśya 'Look at the boy '.

The Instrumental is originally the with-case: it denotes adjacency, accompaniment, association – passing over into the expression of means and instrument. For example: bālakaḥ yānena gacchati 'The boy is going by a vehicle'.

The Dative is the use of the indirect object – toward or in the direction of or in order to or for which anything is or is done (either intransitively or to a direct object). For example: bālakāya pustakaṁ dadāmi'I give a book to the boy'.

The Ablative is the from-case, in the various senses of that preposition; it is used to express removal, separation, distinction, issue, and the like. For example: bāalakāt pustakaṁ ānayāmi' I bring a book from the boy'.

The proper value of the Genitive is adjectival; it belongs to and qualifies a noun-character to the adjective. It generally denotes possession, relationship and connection. For example: bālaksya pitā'Father of the boy' or 'The boy's father'.

The Locative is properly the in-case, the case expressing situation or location. It expresses the place and time in which a thing is done. For example: grāme vasāmi'I live in the village'.

The Vocative is used in the sense of 'addressing' and 'calling to'. But its functional role is like the Nominative, except in the singular number. For example: he bālaka atra āgaccha 'O child, come here!'

All these cases can be summarised in the following way:

1) Nominative – subject

2) Accusative – to (direct object)

3) Instrumental – by/with/through

4) Dative – to/for (indirect object)

5) Ablative – from/than/because of/out of

6) Genitive – of / belonging to

7) Locative – in/on/at/among/upon

8) Vocative – direct address

Adverbs in Sanskrit are either primitive or derived from nouns, pronouns or numerals. They can be simple adverbs and compound adverbs. Simple adverbs may be classified under four heads: a. those formed from the cases of nouns and obsolete words; b. other adverbs of less obvious derivation; c. adverbial suffixes; d. adverbial prefixes.

A large number of adverbs are more or less evidently in case forms. For example: satyam (truly), śīghram (quickly), samīpam (near) are in the accusative;  uccaiḥ (loudly), nīcaiḥ (slowly), cireṇa (after a long time, late), purā (long ago) are in the instrumental; cirāya (for a long time), arthāya (for the sake of) are in the dative; akasmāt (all on a sudden), samantāt (all around), haṭhāt (immediately) are in the ablative; sapadi (at once), ṛte (without), ādau (in the beginning) are in the locative.

Adverbs of affirmation (nūnam 'surely', athakim 'certainly' etc.), negation (na, mā etc.), interrogation (kim 'what' etc.), comparison (iva'like' tathāiva 'like that' etc.), quantity (ativa' very much' etc.),  manner (punaḥ' again', vṛthā' in vain' etc.), time (ādya 'primitive', adhunā 'now' etc.), place (iha 'here',  kva 'where' etc.) are of less obvious derivation.

Classes of adverbs sometimes of considerable extent are formed by the addition of adverb-making suffixes especially to pronominal bases, but also to noun and adjective stems. For example: sarvataḥ 'on all sides', purataḥ ' in front' are formed from the pronouns sarva and pura by the addition of the suffix tas; kadācit 'sometimes', kācit 'someone', kutracit' somewhere' are formed by the addition of the suffix  cit to kadā, kā, kutra; atra 'here',  tatra 'there', kutra 'where' by the addition of the suffix tra.

A small number of prefixes also form adverbs. For example: the addition of the negative prefixes a and an – a to the consonants and an to the vowels–  form adverbs. The words of this type are: aspṛśat (not touching), anuktvā (having not said) etc.

Etmanepada and Parasmaipada

To each Tense belong two sets of personal terminations; one for the Active voice, the other for a kind of Middle or Reflexive voice. The former of these voices is called parasmaipada, because the action is supposed to be transitive, or to pass to another; the latter is called ātmanepada because the action is supposed to refer 'to one's self'. But this distinction, however, is not always observed, and often it is seen that both parasmaipada and ātmanepada are employed for Transitive verbs. Some roots take exclusively Pasamaipada terminations and some ātmanepada, while there are others which take either. Several roots again, though are in parasmaipada, change to ātmanepada and vice versa, when preceded by certain prepositions or in particular senses.

There are six tenses and four moods in Sanskrit. They are: Six Tenses: one Present Tense, three Past Tenses (Aorist, Imperfect and  Perfect), two Future Tenses (the First Future and the Second Future); Four Moods Imperative, Potential, Benedictive and Conditional. The Present Tense belongs to the present period; this Tense, besides its proper use, is often used for the future, for example kim karomi  'what shall I do', and sometimes for the Imperative, for example tat kurmaḥ 'let us do that'; in narration it is used for the past tense; it may also denote habitual or repeated action; the addition of the particle sma to the present form gives it the force of a perfect past. Although the three Past Tenses  are used without much distinctions, yet it should be observed that they properly express different degrees of past time: the Aorist properly expresses 'time indefinitely past' and refers to an event done or past at some indefinite period, whether before or during the current day; the Imperfect denotes past action not done today, it also refers to 'past incomplete action', yet it is commonly used to denote 'indefinite past time'; the Perfect is said to have reference to an event completely done before the present day at some remote period or at some definite period of past time, unperceived by or out of sight of the narrator. It is frequently, however, employed indeterminately. This Perfect past is of two types: Reduplicated and Periphrastic. The Reduplicative Perfect is formed of all monosyllabic roots beginning with consonants, as well as of those beginning with the vowels a ā i u ṛ. The Periphrastic Perfect is formed of all roots beginning with any vowel except a or ā, and of roots having more than one syllable. Out of the two Future Tenses the First Future expresses 'definite' but 'not immediate futurity';  the Second Future, although properly indefinite, is employed to express 'all degrees and kinds of futurity', immediate or remote, definite or indefinite. Among the four Moods the Imperative yields the usual force of 'command' or 'entreaty'; the first person Imperative is used to express 'necessity', for example aham karavāṇī 'I must perform'. The Potential or Optative may generally be rendered in English by one of the auxiliaries 'may', 'can', 'would', 'should', 'ought'. It is said to denote 'command', 'direction', 'expression of wish', 'condition' and 'supposition'. It is also employed in 'indefinite general expressions' and often occurs as a 'softened imperative'. The Benedictive or Precative is chiefly used in pronouncing benediction and also in imprecation. It is a modification of the Potential. The Conditional is used 'when an action is supposed to pass by unaccomplished'. It is occasionally used after the conjunctions yadi and cet, 'if'.

In Sanskrit Comparative degree is formed by adding either the suffix tara or the suffix īyas to a noun base, and the Superlative degree is formed by adding either the suffix tama or the suffix iṣṭha to a noun base. All the words formed by addition of these suffixes are declined in all the three genders.

In Sanskrit simple words, whether substantives, adjectives, verbs or indeclinables can be combined with one another to form what is called a Compound. A Compound may, like a simple word, become a member in another Compound, and this in yet another – and so on, without definite limit. For example: nītiśāstra meaning 'the book of conduct', is a compound word formed by the combination of nīti and śāstra. Another compound word tattvajña meaning 'one who knows the essential principles', formed by the combination of tattva and jñā. Both the above compound words can further be compounded as nītiśāstratattvajña meaning 'the one who knows the essential principles of the book of conduct'.  The Compounds in Sanskrit are divided into six classes: 1. Copulative or dvandva. It consists of two or more nouns which, if not compounded, would all be in the same case connected by a copulative conjunction like ca. guruśiṣyau 'the teacher and the disciple' is one example of this class. 2. Determinative or tatpuruṣa. It consists of two nouns and the first determines the sense of other. If uncompounded the first member of this compound would be in a case different from or dependent on the last. candraprabhā 'moon-light' which actually means the light of the moon is an example of this class. The words belonging to this class are used either as nouns, adjectives or adverbs. 3. Appositional or karmadhāraya. This is composed of an adjective or participle and substantive. The adjective or participle is placed first, and if uncompounded it would be grammatically in concord with the substantive. sādhujanaḥ 'a good man' is an example of this class. 4. The Numeral Appositional or dvigu. Here the stem of a numeral is compounded with a noun, either so as to form a singular collective noun, or an adjective. So one can get nouns like triguṇam 'three qualities', or adjectives like triguṇa 'the one possessing the three qualities'. 5. Attributive or bahuvrīhi. The words belonging to this class are generally epithets of other nouns. These are formed by compounding two or more words to qualify the sense of another word. For example in the word  pītāmbara 'one whose garment is yellow', the word pīta means yellow and ambara means garment, but the compound as a whole refers to a person wearing yellow garment. 6. Adverbial or avyayībhāva. The words of this class are formed by the addition of a preposition or adverbial prefix with a noun. The compound so formed is an indeclinable. adhihari 'in Hari' is an example of this class. The Compounds which do not fall into any one of these categories are termed as kevala Compound. The word avyayībhāva is an example of this category.

There are three numbers in Sanskrit: Singular denoting one; Dual denoting two; Plural denoting three or more.

Combination of clauses takes place by the Conjunctions. The Conjunctions in Sanskrit can be classified under the following categories:

1. Copulative – ca (and), atha (now, and) atho (then).
2. Disjunctive – vā (or).
3. Adversative – athavā and kiṁ vā (or else), tu and kintu (but).
4. Conditional – cet and yadi (if).
5. Causal – hi (since), tat and tataḥ (then).
6. Interrogative – nanu (not?, is it not?, certainly, surely, indeed, no doubt –esp. in questions amounting to an affirmation e.g. nanvahaṁ te priyaḥ 'am I not your friend' i.e. certainly I am your friend).
7. Affirmative and Negative – ām and atha kim (yes).
8. Conjunctions of time – yāvat…tāvat (as long… so long).

These are a few examples of different Conjunctions. ca and vā are never used in the beginning of any sentence. atha and iti are used to mark the beginning and the close of a story or chapter respectively.

A Gerund is an Indeclinable Past Participle which is formed by adding the suffix tvā ((from ktvā) to simple Roots either Primitive or Derivative, and by adding ya ((from lyap) to prefixed Roots either Primitive or Derivative.  For example gatvD 'having gone', anubhūya 'having felt'. A Gerund is usually translatable by the English 'having', 'when', 'after', 'by'.

An Indeclinable undergoes no change, remains the same in all the Genders, Numbers and Cases. All the Indeclinable words in Sanskrit are divided into simple and compound ones, and comprise Prepositions, Adverbs, Particles, Conjunctions and Interjections.

An Infinitive is formed by adding the suffix tum to the Primitive or Derivative Roots, and is used as a verbal noun with the force of the Accusative or Dative case.

Participles are words derived from verbs by adding different suffixes in different senses. These are used as verbal phrases and as adjectives. All the Participles fall into two groups declinable and indeclinable. To the declinable Participles belong: the Present Active Participles like paṭhat 'reading'; the Present Passive Participles like kriyāmāṇa 'being done'; Past Active Participles like gatavān 'went'; Past Passive Participles like gata 'gone'; the Participles of the Simple Future, Active, like kariṣyat and kariṣyamāṇa 'about to do', Passive, like vakṣamāṇa' about to be said'; the Participles of the First Future, also known as Potential Participle or Gerundives, like kartavya 'to be or must be done', darṣanīya 'to be or must be seen', deya 'to be or must be given'. To the indeclinable Participles belong the $Gerunds$ and the Infinitives .

There are two Negative particles: na signifying simple negation and mā signifying prohibition. The Negative particle na is added to a noun to form a negative Compound. This particle na changes to a before a consonant and to an before a vowel. For example: na brāhmaṇaḥ becomes abrāhmaṇaḥ and na aṣvaḥ becomes anaṣvaḥ. The Imperative negative or prohibitive is usually expressed by the particle mā. For example tatra mā gaccha 'do not go there'.

The Verbal Roots in Sanskrit are either Primitive or Derivative. There are about 2000 Primitive Roots grouped under ten different classes, and the Derivatives are derived either from these Primitive roots or from noun bases by addition of various suffixes. The Derivative Roots are of four categories: Causative or Causal, Desiderative, Frequentative, Denominative. Any Root belonging to any one of the conjugational classes may have a Causal form and is conjugated in all Tenses and Moods of the three voices [see14]. The Causal of the Root implies that a person or a thing causes or makes another person or thing to perform the action, or to be in the condition denoted by the Root. For example paṭhati 'one reads' in its Causal form becomes pāṭhayati 'makes someone read'.   It is also employed, sometimes, to convert an intransitive verb into a transitive one. Similarly any Primitive Root of any conjugational class may optionally take a Desiderative form, which, is conjugated in all the Tenses and Moods of the three voices. The Desiderative expresses the notion that a person or thing wishes to perform the action. For example paṭhati 'one reads' in its Desiderative form becomes pipāṭhiṣyati 'one wishes to read'. A Frequentative or Intensive form can be derived from any monosyllabic Root of the first nine classes, beginning with a consonant. The Frequentative is used to signify the repetition or the intensity of the action denoted by the verb from which it is derived. For example dipyati 'shines' in its Frequentative form becomes dedipyate 'shines intensely'. When a Root is derived from any noun base by addition of certain suffixes it is called Denominative. The Denominative Roots are not very much in use and are generally used in the Present Tense. Sometimes they convey the notion of performing, practising, or the quality expressed by the noun, and are used transitively; sometimes they express the idea of acting, behaving or becoming like the person or thing expressed by the noun. The Passive verbs are also considered to be Derivatives. These are formed by adding ya to the Primitive Roots, and are conjugated like an ātmanepadi Root. Thus we get words like gamyate 'is gone', dṛṣyate 'is seen'.

Nouns are of three genders: Masculine, Feminine and Neuter. The gender of a noun is, in many cases, determinable from the termination of its stem. Thus, nearly all stems in ā i, and those formed with the suffix ti are feminine; most abstract nouns and those denoting an act or instru­ment, formed with the suffixes ana, tva, ya, tra, as, is, us, and man, are neuter; those formed with the suffixes na and iman are generally masculine; but those in   a i u ṛ, and ṛ are generally not determined by any rule. The Nominative case is, however, in the first of these instances a guide to the gender; as, devaḥ, 'a deity', is masculine; but phalam, 'a fruit', neuter. And in other cases the meaning of the word determines the gender, as, pitṛ, 'a father', is masculine; and mātṛ, 'a mother', feminine.

It may be noted also that words denoting gods, mountains, seas, divisions of time, are generally masculine; words denoting rivers, the earth, and night, are usually feminine; while adjectives and participles, used as abstract nouns, the names of woods, flowers, fruits, towns, and water, are generally neuter.

There are three voices in Sanskrit: Active Voice, bālakaḥ satyaṁ bhāṣate 'the boy speaks the truth'; Passive Voice, bālakena pustakam paṭhyate 'the book is being read by the boy'; Impersonal Voice, bālakena hasyate 'the act of laughing is being performed by the boy'. All transitive verbs are conjugated in the Active and Passive Voices, and all intransitive verbs are conjugated in the Active and Impersonal form. In an Active sentence the agent is put in the Nominative case and the object in Accusative. The number and person of the verb is according to the number and person of the agent. In a Passive sentence the agent is in the Instrumental case and the object in Nominative with the verb in its Passive form. Here the verb is always in the third person and the number is according to the number of the object. In an Impersonal construction the agent is in the Instrumental case and the verb is in its Passive form. Here the verb is always in third person singular.

There are three Persons First Person referring to 'I/we'; Second Person referring to 'you'; Third Person referring to 'he, she' etc. Each of these take their own conjugational forms. But the pronoun bhavat denoting respect towards the Second Person, takes Third person verbs, and is formed in all the three genders. Thus for 'you are going' one gets bhavān or bhavati gacchhati, not gacchasi.

There are 35 basic Pronouns in Sanskrit from which many others can also be derived. All the Pronouns are classified into 9 different categories. 1. Personal Pronouns like asmad 'I', yuṣmad 'you'. These two have no genders. 2. Demonstrative Pronouns like tad 'he, she or that', etad 'this',  idam 'this' and adas 'that'. These have different forms in the three different genders. 3. Relative Pronoun yad 'who, which' formed differently in different genders. 4. Interrogative Pronoun kim 'what, which, who', is formed differently in different genders. 5. the Reflexive Pronoun in Sanskrit is expressed by the word ātman 'self' which is invariably used in the masculine gender and singular number, and by the reflexive adverb svayam. 6. Indefinite Pronouns are formed by the addition of suffixes cit or cana or api and sometimes of svit to the various cases of the Interrogative Pronoun kim in all the genders. Thus one gets words like kaścit, kācit 'someone, anyone' kimapi 'something, anything' etc.  7. Correlative Pronouns are formed by the addition of suffix vat to yad, tad, and etad; the suffix yat to idam and kim in the sense of 'as much as'; and dṛśa or dṛś in the sense of 'similar to'. tāvat 'that much', kiyat 'how much', īdṛśa 'like this' etc. are examples of this category. 8. Reciprocal Pronouns are formed by repeating the pronominal adjectives anya, itara and para. Thus the words like anyonya, itaretara, 'one with another' paraspara 'each other' etc. are of this type. These are generally used in the singular and also adverbially. 9. Possessive Pronouns are formed by means of the secondary suffix īya added to tad, etad, asmad and yuṣmad. So one gets words like asmadīya 'that which belongs to us', tvadīya 'that which belongs to you' etc. The words māmaka, māmakīna meaning 'my/mine', tāvaka, tāvakīna meaning 'thy/thine' in singular and āsmāka, āsmākīna meaning 'our/ours', yauṣmāka, yauṣmākīna meaning 'your/yours' are also Possessive Pronouns.