In the middle or at the end of a sentence, we do not typically use a comma before or after “occasionally” or “sporadically”. However, there are particular sentence constructions where commas may be used.

If a sentence is clear, the comma after an adverbial prepositional phrase at the beginning of a clause is optional. However, the longer the introductory phrase, the more likely you will place a comma after it.

At the beginning of a sentence, we usually put a comma after the introductory phrases “when in doubt”, “in case of doubt”, “beyond doubt”, etc.

At the start of a sentence, we usually add a comma after introductory phrases, such as “on this occasion”, “on numerous occasions”, “on many occasions”, “on occasion”, “on a number of occasions”, “on the occasion of...”, etc.

At the beginning of a sentence, using a comma after short prepositional phrases, like “at times” or “at all times”, is generally optional.

At the beginning of a sentence, add a comma after the expressions in the context of..., within the context of..., etc. to signal that the introductory phrase applies to the sentence as a whole.

At the beginning of a sentence, adding a comma after the prepositional phrases “in the long run”, “in the short run”, “over the long run”, or “over the short run” is often optional.

When using the expressions in the short/medium/long term, over the short/long term, or for the long/short term at the beginning of a sentence, the comma is commonly optional; that is, it can be easily omitted if the sentence is concise or clear.