[pasquinelli]

sort of related: it drives me crazy when people use a question mark to show doubt, (sometimes sarcastically), instead of to ask a question. i've never seen (?) before, but i see "i think mark said he was done?", a lot.

even though it drives me crazy, it shows that special punctuation is unnecessary. people can just keep doing that awful thing, and there's no real ambiguity.

[nonsince]

Many people raise the pitch of their voice as if asking a question when saying something doubtfully, so the question mark reads similarly to how one would say it out loud.

If you have access to formatting, a similar way of achieving the same thing would be to italicise "think"