@flat soft liG derivations

third person

**yAt' यात्ऽ "may he"

**yAstAm यास्ताम् "may both"

**yAsus यासुस् "may they"

second person

**yAs' यास्ऽ "may you'"

!**yAstam यास्तम् "may you''"

!**yAsta यास्त "may you'''"

first person

!**yAsam यासम् "may I"

!**yAsva यास्व "may we2"

!**yAsma यास्म "may we3"

Note that the soft **yAt' यात्ऽ and **yAs' यास्ऽ look like the hard **yAt यात् and **yAs यास्. So soft **dviSyAt' द्विष्यात्ऽ and hard **dviSyAt द्विष्यात् sound the same.

But if the verb base ends in a अ, the hard **yAt यात् **yAs यास् become it इत् is इस् by atoyeyaH, so we get soft **bhUyAt भूयात्, hard **bhavet भवेत्.

See also flat soft liG overview.

The flat soft liG endings are —

**yAt' **yAstAm **yAsus
**yAs' **yAstam **yAsta
**yAsam **yAsva **yAsma

How do the sUtras form these?

Starting with the flat basic tiG, we replace the /jhi with /jus by jherjus. The other eight get the same changes as in the flat laG, namely tasthasthamip..., 1itazca or nityaGGitaH —

/t''' /tAm''' /jus
/s''' /tam''' /ta'''
/am''' /va''' /ma'''

After that, rule yAsuTparasm... adds yAs in front —

yAst **yAstAm **yAsus
yAss **yAstam **yAsta
**yAsam **yAsva **yAsma

And then yAst and yAss lose their nexttolast by skossaMyogAdy....

If you need that explained in detail, see flat soft liG verbose derivations.