An introductory adverb clause is usually followed by a comma an within sentence does not require punctuation?

You're almost right! Here's a breakdown of adverb clauses and punctuation:

Introductory Adverb Clauses

* Yes, they are usually followed by a comma. This is because they modify the main clause that follows them.

* Examples:

* After the sun set, the sky turned a vibrant orange.

* Because she was tired, she went to bed early.

Adverb Clauses Within a Sentence

* They do not require punctuation unless they are parenthetical.

* Example: He was happy, although he didn't show it.

Why We Use Commas

* Clarity: Commas help separate the introductory clause from the main clause, making the sentence easier to understand.

* Grammatical Structure: They signal that the introductory clause is modifying the main clause.

Let me know if you'd like more examples or have any other questions!