en_tn/1co/14/15.md

What am I to do?

AT: "This is what I will do" (See: rc://en/ta/man/translate/figs-rquestion)

pray with my spirit...sing with my mind

This refers to praying or praising in tongues.

with my mind

This means with words that I understand.

you praise God...you are giving thanks...you are saying

Though "you" is singular in this instance, Paul is addressing everyone who prays only in the spirit, but not with the mind.

the outsider

AT: "another person"