Split Infinitive

Split infinitive are not grammatically incorrect but we need to avoid in formal writing and speaking.

Infinitive:

• to swim
• to run 
• to cook

Example:

I have to quickly cook, I will be late.(Not this)

I have to cook quickly, I will be late (But this)

I want to well do my homework.(Not this)
I want to do my homework well.(But this)