Using preposition to and for after verbs to go and to leave

English as a Second Language English Vocabulary, Grammar and Idioms
1

Why should I use I WENT TO and I LEFT FOR. Why can’t I say I left to Mombai?

2

I think it’s simply a structure. Sometimes there are some English structures or phrases, which don’t following any rules. So, the best thing we could is compulsorily learn them by heart.