Personal pronouns are genderless and do not have a specific form for the 3rd person which is provided by demonstrative pronouns. They are inflected in all cases except the vocative. Some cases have shorter, enclitic, forms that are those most frequently used.
Demonstrative pronouns distinguish gender and are also fully inflected. There are five of them (three proximal and two distal). The most frequent are ayam ('this') and sa ('that').
There is just one interrogative pronoun ('who?/what?') whose nominative singular is: kaḥ (masculine), kim (neuter), kā (feminine); except the nominative/accusative neuter singular (kim) it is inflected like the demonstrative sa. Indefinite pronouns and adverbs are derived from the corresponding interrogatives by adding the particles cit, cana or api.
The relative pronoun has the following nominative singular forms: yaḥ (masculine), yat (neuter), yā (feminine). It introduces relative clauses and, like all other pronouns, is declined in seven cases and three numbers (it follows the declension of the demonstrative sa).
The reflexive pronouns are ātman and svayam. The first one is declined in masculine singular for all genders, numbers and persons. The second one is invariable.
•articles: Sanskrit has no articles but demonstrative pronouns can function as definite articles, and indefinite pronouns as indefinite ones.
•compound words: Vedic Sanskrit had, like Indo-European, the capacity to form compound words, joining two, or at most three, words (usually nouns). Classic Sanskrit expanded this capacity by combining all sorts of nouns, adjectives, pronouns, adverbs, particles and verbal roots in compound words that can be very long (from 2 to 15 members or more). In a compound only the last word is declined, the others appear in their stem form.
There are four main compound types:
a)copulative, or dvandva in which two or more nouns or adjectives bear a relationship between them as it would be expressed by 'and' in English:
This compound is declined in the dual number indicating that there is one teacher and one pupil. If there were more than one of them the compound would be in the plural.
b)descriptive or karmadhāraya in which the first element stands in an attributive relation to the second:
A black bird.
c)dependent or tat-puruṣa in which the head is involved in a relationship with the other members of the compound as it would be expressed by an oblique case (from accusative to locative):
Here, the relationship is a genitive one.
d)exocentric or bahu-vrīhi in which the whole compound qualifies a word outside itself:
This type of compound usually ends in a noun that behaves like an adjective agreeing in case, gender and number with the word it qualifies. In the example, even if mukha is a neuter noun it is declined as masculine to agree with naraḥ.