Do you have to write a comma in this sentence Lately he is making an effort and?

The sentence "Lately he is making an effort and" is incomplete. You need to add a second clause to complete the thought. Here's how the comma works:

* If the second clause is independent (meaning it can stand alone as a sentence), you need a comma before the conjunction "and":

* "Lately he is making an effort, and he's starting to see results."

* If the second clause is dependent (meaning it relies on the first clause for complete meaning), you don't need a comma:

* "Lately he is making an effort and is showing improvement."

Let me know if you want to complete the sentence and I can tell you if you need a comma!