Upper Intermediate - Silencing weak verbs

Don't get it lads.the second part you don't write the sukuun.any particular reason?

@Plop, You mean (lam ya3lu, la a7'sha ...) in the transcript ?

Ok . No it is the explanation related to the mu3tal verbs I do not get.do you say you can't silence them and hence no sukuun?

Plop, perhaps the section "signs of the jussive mood" here: http://arabic.tripod.com/MoodSigns.htm . From what I can tell the zukuun is not used. In the example of the transcript the feminine form of address has no zukuun, but in the "signs of the jussive mood" a zukuun is written anyway after the ya.

thanks a lot - great tip - cheers