deriv SD cv (343) ashtadhyayi.com hei.de L 343 ETT STT a 7.2.88 ALPH OLDHOMEPAGE NEWHOMEPAGE

prathamAyAz ca dvivacane bhASAyAm

प्रथमायाश्च द्विवचने भाषायाम् ONPANINI 72088

Before first, (yuvam युवम् Avam आवम् lengthen their nexttolast) when dual in the /laukika.

/yuSmad- + /au
→ yuvam युवम् + /au by yuvAvaudviv... >>>>
→ yuvam युवम् + /am by
→ yuvAm युवाम् + /am by this rule
→ yuvA युवा + /am
→ yuvAm युवाम्
→ !**yuvAm युवाम्

!**AvAm आवाम्, same steps as **yuvAm युवाम् above.

Why do we say "in the /laukika"?

This lengthening is optional in the veda: yuvam युवम् Avam आवम्.

What happens before second dual?

Then we still get yUvAm यूवाम् AvAm आवाम्, but this time by < dvitIyAyAJca —

/yuSmad- + second /au
→ yuvam युवम् + /au
→ yuvam + /am
→ yuvAm + /am by < dvitIyAyAJca
→ yuvA युवा + /am
→ **yuvAm' युवाम्ऽ