Learn Dutch: Durf jij meer moeite te doen? - Do you dare to make more effort?

The main verb in this sentence is durven (to dare). When durven is used with a second verb, that second verb must be an infinitive (the full dictionary form) with te placed right in front of it. This is why we get te doen.

Why are we using doen (to do) instead of maken (to make) for 'to make an effort'?

This is a fixed expression. In English, you 'make' an effort, but in Dutch, you always use doen (to do) with moeite. So 'to make an effort' translates as moeite doen.

Why is te doen placed at the very end of the sentence?

In Dutch questions, the first verb (durf) swaps places with the subject (jij) and goes at the beginning. Any other verbs get pushed all the way to the end. Since te always sticks directly to its infinitive, the whole piece te doen goes to the very end.

Could I say Durf je instead of Durf jij?

Yes, you absolutely can! We use jij here to put a little extra emphasis on 'you' - as in, 'Do you dare to make more effort?' If you just want to ask a neutral question without that extra stress, Durf je is perfect.