You picked the right verse.
The other one that goes with it is this one:
2Pe_1:21 For the prophecy came not in old time by the will of man: but holy men of God spake as they were moved by the Holy Ghost.
It's not an all or nothing event. God decides WHAT is to be spoken, the person provides when/if it will be spoken. It is an agreement between the two....in the case of both prophecy and speaking in tongues. But there are these differences:
Prophecy is spoken in a language understood by both the speaker (man) and the hearer (man).
(unknown)
Tongues is spoken in a language understood by only the intended hearer (God) and not the speaker (man)...unless God provides the interpretation.
Diversities of tongues (a spiritual gift like prophecy or laying on of hands for healing) is spoken in a language understood by the hearer(s) (men) but not the speaker (man). Basically, as far as the speaker knows, he is just delivering a message in (
unknown) tongues, but the syllables coming out are actually the language of the hearer. The speaker doesn't necessarily know this because, again, he doesn't understand the language coming out his mouth.
In all of these, God has to provide the content.. man has to allow it to come out his mouth. It is an agreement, not one-sided.
BTW, it was diversities of tongues that was occurring in Acts 2 AFTER the initial outpouring of unknown tongues. Please notice that the multi-lingual crowd wasn't present initially. They were drawn because of the original outpouring.
(I'm guessing many hadn't even heard of that last one before now)
Love in Jesus,
Kelby