"At her age one could never tell but my grandmother could".What would one never tell?What was grandmother sure of?

The grandmother’s response when the author left and even when he came back after five years remained the same. She did not have any words to share with him. She kept on reciting prayers continuously. She did not seem a day older. She had not changed much which was visible when she kept feeding the sparrows even after the return of her grandson. Therefore, no specific reason has been mentioned here as to why the grandmother did not respond when the author left. 

 sryyy bt i dnt think so it izz d xact ans which i wunt!

I think at her(grandmother's) age one could never tell(it means giving permission for going abroad) but her grandmother(emphasized as a strong woman) could tell(allow him to go abroad). Moreover, she did not show any emotions during his departure.

This is basically the idea of the Answer.

You can frame your own Answer using this.

If u have any problem then Plaese Let me Know.

Regards,

Ashi Jain

 no yrrrr....thiz too iz nt d ans....i think itz sumthin relatd to er death...i mean 2 say one cud neva tell wn she'z goin 2 die....sumthin lyk tht u noeee!wat ya say?

i thmk author contemplated on his grand mother not being alive till the time he came back.

Yeah, I guess you are correct..!!

Experts...!! Please help :)