Do I always have to place a comma right before "too" in the end of a question?:
... and those were completely different kind of problems to solve. Those were called "complimentary problems". They were not to be solved by us immediately, however, solving them required some additional wit and shrewdness. So, I want to ask the moderator if he minds if I say a few things about those problems, too?
Will this question be understood wrongly I decide to omit the comma?
The Chicago Manual of Style writes that putting a comma before 'too' is preferred to show a significant shift in thought.
He didn’t know at first what hit him, but then, too, he hadn’t ever walked in a field strewn with garden rakes.
The same thing is mentioned in Grammarly:
Since it really depends on the writer’s intent, there is no hard-and-fast rule when it comes to using a comma before too. Remember that commas often denote a pause, especially when emphasis is intended, so reading the sentence aloud and listening for a pause may be helpful.
So, no, it won't be understood wrongly. And, there is no such thumb rule.
The Chicago Manual of Style (17th ed.), 6.52, says (I cannot provide a link as it's behind a paywall for the online version):
The adverbs too and either used in the sense of “also” generally need not be preceded by a comma.
I had my cake and ate it too.
Anders likes Beethoven; his sister does too.
The airport lacked charging stations; there were no comfortable chairs either.When too comes in the middle of the sentence or clause, however, a comma aids comprehension.
She, too, decided against the early showing.
So, if too is at the end of a sentence, as in your question, then Chicago would likely not use a comma; if it's in the middle of a sentence, then it probably would.
This is more direct than what is relayed by the FAQ entry provided in the other answer. But if you look at the full text of that entry, you'll see there's more to it and that it gives similar examples:
A comma can do some work in making the meaning of a sentence clear, but to claim two different meanings for I like apples and bananas too with and without a comma before too puts too much pressure on the comma. Out of context, neither version would be perfectly clear. To make the different meanings more apparent, short of additional context, you’d have to be more explicit:
I, too, like apples and bananas.
I like not only apples but bananas too.
No, rather I think the writer was a little excessive with the commas. While I think you should place commas surrounding clauses, putting clauses in the middle of sentences also means adding two breaks and not just one. This isn't even a clause, but a deliberate pause at the end. Perhaps the writer was expressing artistic license?
Though again, in short, no. The comma contributes nothing other than a quite possibly unnecessary pause at the end.
