Do you have to put a comma after word in the series then and?

You don't need a comma after "then" in a series unless there is a conjunction like "and" or "or" before it.

Here's why:

* Series Structure: A series of items is usually separated by commas, with a conjunction (like "and" or "or") before the last item.

* "Then" as a Conjunction: "Then" acts as a conjunction, but it's usually used to show sequence, not to connect items in a series.

Examples:

* Correct: We ate breakfast, went for a walk, and then did some gardening.

* Incorrect: We ate breakfast, went for a walk, then did some gardening. (This sounds awkward and might imply a pause before "did some gardening.")

When to use a comma:

* If "then" is part of a longer phrase with a conjunction before it: We ate breakfast, went for a walk, and then, after a short rest, did some gardening.

In summary: The rule of thumb is to only use a comma after "then" in a series if a conjunction like "and" or "or" comes before it.