Vectorline is spot on
If you have a phraseology handbook (not sure if your civilian school produce one like they do at CATCS, the military school in the UK) record the aircraft transmission and leave a gap sufficiently long enough for you to reply, then record the correct response. Play it in the car, in the kitchen, on the toilet etc and compare your efforts with the correct RT. Keep it playing everywhere until:
a. you know it and
b. you feel comfortable using the RT.