Weird sentence structure

Question

I've found one interesting expression on Google Translate that violate syntax grammar rules:

Oh heck, I can't for the life of me remember

I don't see the main verb just after the auxiliary one. What the syntax grammar rule used here?

Answer 1

The main verb usually goes right after the auxiliary verb, but that's not always the case. In fact, adverbs tend to go between the two.

The phrase 'for the life of me' is used as an adverb, so

I can't for the life of me remember

is similar in structure to

I can't rightly remember

both of which are perfectly valid English sentences.

Answer 2

If you set off the expression for the life of me (click on this link to find out what this phrase means and how to use it) with a pair of commas, it will become crystal clear what the main verb of this sentence is:

Oh heck, I can't, for the life of me, remember.

It's remember, as I hope you can now clearly see. At no time did this sentence violate any rules of English grammar. If it's still difficult for you to mentally parse this sentence, let's move the expression for the life of me out of the way and place it right before I:

Oh heck, for the life of me, I can't remember.

Do you think you can read it better now?

Adverbials (or adverbial phrases) are flexible creatures in English in that many times you can't freely move them around in your sentences without structurally and grammatically breaking them.