Sanskrit demonstrative pronouns have a declension similar to adjectives.


Pronoun saḥ, sā, tat
This pronoun is translated most often as "he, she, it". It is declined like words with -a- and -ā- stem (ta-, tā-) except nom.sing., but it has some exceptional forms:
in masc. and neutr. with added -asm- : dat. sing. tasmai, abl. sing. tasmāt, loc. sing. tasmin
in fem. : with added -asy- : tasyai, tasyāḥ, tasyām
nom. pl. masc. te, gen. plur. masc.neutr. teṣām
saḥ, sā, tat : singular

case	masculinum	neutrum	femininum
nom. voc.	saḥ	tat	sā
acc.	tam	tat	tām
instr.	tena		tayā
dat.	tasmai		tasyai
abl.	tasmāt		tasyāḥ
gen.	tasya		tasyāḥ
loc.	tasmin		tasyām

Plural:

case	masculinum	neutrum	femininum
nom. voc.	te	tāni	tāḥ
acc.	tān	tāni	tāḥ
instr.	taiḥ		tābhiḥ
dat.abl.	tebhyaḥ		tābhyaḥ
gen.	teṣām		tāsām
loc.	teṣu		tāsu

Dual:

case	masculinum	neutrum	femininum
nom. acc. voc.	tau	te	te
instr.dat.abl.	tābhyām		tābhyām
gen.loc.	tayoḥ		tayoḥ

Pronoun ayam, idam, iyam
This pronoun is also declined like words with -a- and -ā- stem (a-, ā-) except nom. sing. Its stem is ima- / imā- in nom. acc., and a- / ā- in other cases. It has some exceptional forms: it adds -asm- and -asy- in dat. abl. loc. sg. and has nom. pl. masc. ime, gen. plur. masc.neutr. eṣām. Exceptional is instr. plur. ebhiḥ. Three forms begin with an- : anena, anayā, anayoḥ.
ayam, idam, iyam : singular

case	masculinum	neutrum	femininum
nom. voc.	ayam	idam	iyam
acc.	amam	idam	imām
instr.	anena		anayā
dat.	asmai		asyai
abl.	asmāt		asyāḥ
gen.	asya		asyāḥ
loc.	asmin		asyām

Plural:

case	masculinum	neutrum	femininum
nom. voc.	ime	imāni	imāḥ
acc.	imān	imāni	imāḥ
instr.	ebhiḥ		ābhiḥ
dat.abl.	ebhyaḥ		ābhyaḥ
gen.	eṣām		āsām
loc.	eṣu		āsu

Dual:

case	masculinum	neutrum	femininum
nom. acc. voc.	imau	ime	ume
instr.dat.abl.	ābhyām		ābhyām
gen.loc.	anayoḥ		anayoḥ