I'm a native Cantonese speaker, so in Cantonese I use 食 as a verb and hardly ever use 吃, but in Mandarin, 吃 replaces 食 as the verb "to eat". Because of that I'm not sure when to use 食 in a correct grammatical sense in Mandarin.
I'm 100% sure 食 isn't just one of those Cantonese-only words (like 哋 or 唔) and is used in Mandarin, so my question is: when do I use 吃 and when do I use 食 in Mandarin?
Thanks.