omitting infinitive

English as a Second Language English Teacher Explanations (ESL Tests)
1

Hello Beeesneees.

why ‘‘to’’ is omitted in this sentence?

I’ll go get milk.

thanks

2

Omitted where?

These are all idiomatically correct and common forms of ‘go’ (and ‘come’) + verb in English:

I’ll go/come get milk.
I’ll go/come and get milk.
I’ll go/come to get milk.

3

Thanks sir.