The rule, per Purdue OWL, is that you should not put a comma between the two verbs or verb phrases in a compound predicate. "John" is the subject of the sentence.

Last week, we started discussing the differences between a phrase, clause and a sentence. We defined a phrase as a group of words without a subject and a predicate, though standing together to ...

Secretary of State Mike Pompeo, it seems, is a little obsessive about commas. According to press reports, he’s been sending out directives to staff that they should follow certain strict ...

And now, commas in compound predicates. Here's a sentence that came in with a comma. between the elements of the compound predicate. His mother, Rachel Faucette, the daughter of an Englishwoman.

A dependent clause cannot stand alone, though they often contain both a subject and a verb. Where independent clauses express complete thoughts, dependent clauses do not, and left on their own, ...

Last week, we started discussing the differences between a phrase, clause and a sentence. We defined a phrase as a group of words without a subject and a predicate, though standing together to ...