Breakdown of Je ne savais pas comment m'y prendre.
je
I
ne
not (used before the verb)
pas
not (used after the verb)
comment
how
Questions & Answers about Je ne savais pas comment m'y prendre.
How does the meaning of prendre change when it becomes s'y prendre?
The base verb prendre usually means to take. When it becomes the idiomatic pronominal verb s'y prendre, the meaning shifts entirely to going about something, handling a situation, or tackling a task. The pronoun y here is part of the fixed expression and represents the situation or task at hand.
Wait, I learned that knowing how to do something is just savoir plus an infinitive. Why is comment used here?
That rule applies to acquired skills! For a learned ability like swimming, you drop the word for how and just say Je sais nager. But when you are talking about figuring out the method or procedure to handle a specific situation, you use savoir comment followed by the infinitive, exactly like in English.
Why is the verb prendre left in the infinitive here instead of being conjugated?
It stays in the infinitive because it serves as the action for the question word comment. Just like in English (how to go about it), the verb following the question word remains unconjugated. However, notice that the reflexive pronoun still has to match the subject je, which is why it is m' (a contraction of me) rather than the default dictionary form se.
How would I use this expression in everyday French to say someone is doing a bad job at a task?