Is this sentence correct or am I missing a comma? Is there a way to rewrite it so that it sounds better?

I have learned how to properly write a complete sentence and to avoid run ons and fragments.

You don't need a comma, but it would read better if you put "properly" after the word "sentence."

Your sentence is written correctly. It doesn't need a comma.

You could also say:

I have learned to write a complete sentence and avoid run ons and fragments.

Thank you both! I appreciate your time

You're very welcome.

To analyze whether the sentence is grammatically correct and if a comma is required, let's break it down into its components:

"I have learned how to properly write a complete sentence and to avoid run ons and fragments."

This sentence consists of two main clauses linked by the coordinating conjunction "and." An important rule to consider here is the use of the Oxford comma, which is optional but can help clarify the meaning of the sentence. The Oxford comma is the comma used after the second-to-last item in a list of three or more items.

In this case, the sentence contains a list of three items: "write a complete sentence," "avoid run ons," and "fragments." So, to follow the Oxford comma convention, it would be better to include a comma after "run ons" for clarity:

"I have learned how to properly write a complete sentence and to avoid run ons, and fragments."

Additionally, if you would like to improve the flow and make the sentence sound better, you can consider rephrasing it. Here's a suggestion:

"I have learned the proper techniques for writing complete sentences, avoiding run-ons, and eliminating fragments."

By rephrasing it this way, the sentence becomes more concise and easier to read.