Translation:Mother who will go
The honorific form of 갈 is 가실. 시 is injected between 가 and ㄹ.
Or more accurately, (으)시, the particle of honor, is added to the root before other bits are.
Can someone put this in a sentence as this fragment isnt making sense to me
Imagine lots of mothers have been invited on a holiday, but only one mother can afford it. So which mother will go? "the mother who will go has money" 가실 엄마 돈이 있어 (corrections welcome!) I agree it's not a very natural English sentence, but demonstrates the grammar point.