I am not sure where I got the idea that a comma must be added before "so that", but I have been doing this for a while now, and now I realized it might be ungrammatical, or is it? When would you add a comma?
For example:
You should do several of the things that he asked you to do so that he
doesn't blame you for his failure.
Best Answer
You do not put a comma before "so that". Refer to this thread on wordreference, for example: https://forum.wordreference.com/threads/comma-before-so-that-conjunction-she-pulled-him-to-the-side-so-that.2974733/ Side note: The last two sentences seen in the first post are incorrect. A better way of writing those sentences are:
Commas go before the subordinate clause. "So that" pertains to a situation where someone does something in order to have an intended effect.
I do agree that placing a comma in your example works for the sake of cohesion. However, it isn't correct, strictly speaking, in terms of grammar. It is up to you and whether you prioritize being a stickler for the oftentimes convoluted rules of the English language, or you prioritize your audience understanding you.