To comma or not to comma

[stewamax]

I was recently editing/proofing a dissertation (in English) for someone in Germany. Her English was very good but I noticed that she had used a comma after each occurrence of a Thus or Therefore, especially when it started a sentence.

For example:
“Thus, my assertion is correct”.

It is obviously correct to insert a comma if the immediately following text is a subordinate clause, e.g.
Thus, as I have shown, my assertion … etc”

but in spoken English the first example reads better without a comma, although perhaps would not be so if the Thus was replaced by a longer clause.

Any opinions which is correct?

[servodude]

I have seen both.

Personally I would use the comma in the start of a sentence case, but I would not expect most readers to care.
However, I would expect it to be consistent throughout the document.

I think the comma works because there is a natural "breath" in my reading of these adverbial starts; it is like a variation of "and thus," which avoids a run on sentence.

I do not have anything to back this up though, and it has prompted me to seek out a copy of https://www.amazon.co.uk/A-Study-Of-Sta ... B002VKA2X2 to show my kids what we had to put up with.

Thanks

- sd

[todthedog]

I would go with a comma wherever you would pause when reading.

[stewamax]

<really pedantic>

It is (or was) customary to insert a comma after however and composite prepositions such as all the same when these were at the start of a sentence but not to do so for thus. Inserting one after therefore appears arguable: Wikipedia says I should but my venerable "You have a point there" (Partridge 1953) says not.

My uneducated feeling is that if the preposition is a single syllable or is iambic (i.e. has stress on the last syllable or all syllables),then the comma is omitted because in spoken English the stress and raised intonation then normally runs through to the next word ("Therefore the motion is carried")

</really pedantic>

[richfool]

There is theoretically, a pause, inferred or otherwise, after thus and therefore. (Commas normally match where there is a brief pause for breath except where 'and' is involved). I would suggest therefore, that it is entirely up to the writer and how significant an issue or pause they consider it to be.

Personally, I would base my decision whether to include a comma, or not, based on how significant a pause I wanted and the overall flow of the sentence. For example, if the sentence was short, I would probably not insert a comma. If however the sentence was long and continued by way of a list or several bullet points, I might well include a comma.

[bungeejumper]

It's the German style to use the comma in this sort of situation, so it's not so very surprising that she went for it when writing in English. But actually I agree with Richfool that it can be a useful convention, because the comma inserts a pause into the flow of the sentence which may help the reader to anticipate the shape of what's to come. Not just in this situation, but elsewhere too.

Strictly optional but useful. As Lynne Truss (Eats Shoots and Leaves) also says.

BJ