When using "obviously" or "naturally" as regular adverbs, to modify a single word, we do not typically place a comma to separate them from the verb, adjective, or adverb they describe.

When reflecting the speaker's judgement or opinion, the sentence adverbs "apparently" and "presumably" should be followed by a comma at the beginning of a sentence.

When introducing a clause with a sentence adverb, such as "oddly", "curiously", "ironically", or "surprisingly", add a comma after it.

Set off the sentence adverbs "personally" and "confidentially" with commas to express your opinion or say something in a way that is intended to be private.

When expressing your opinion, attitude, or judgement, use commas to set off the words "frankly", "honestly", "truthfully", or "admittedly".

At the beginning of a sentence, follow the sentence adverbs "sadly", "unfortunately", "regrettably", and "unhappily" with a comma.

In front position, the sentence adverbs "fortunately", "happily", and "luckily" should be followed by a comma. Commas are generally unnecessary when these adverbs modify a single word (verb, adverb, or adjective).

When acting like an introduction at the beginning of a sentence, add a comma after the expressions "generally", "generally speaking", or "in general".