Phrasal verbs! (ie. Not single-word verbs, but phrases that make up a verb.) You just need to learn them in context. This means finding proper sentences you can use, instead of matching the phrasal verb to a definition. Memorizing a list of phrasal verbs is, in practice, not a good idea. Phrasal verbs are flexible things, so the meaning can change entirely if the sentence changes. And yes, you need to make yourself speak phrasal verbs, even if you have to stop yourself and begin your sentence again. It'll become easier with practice.

Hi, Carlos! As non-native English speaker, I can say I understand you. Like you, I've memorized a relatively good number of them, but, as you're now experiencing, it might be challenging to put phrasal verbs into practice. I believe that, once you know what they mean, you should push yourself to use them whenever you can. That's what I used to do when I first started learning about this topic, I'd look for chances to use them all the time, and I'd use them even if it sounded a bit forced then, or I'd try and make up a situation in which they could be part of my vocabulary choice, etc. After some time, you'll find out that they aren't that difficult, it's just that you were not used to them before. Actually, I believe the best method to learn anything is exposure, intellingent and planned exposure, since our brain uses imitation abilities to reproduce what we learn from others. I hope it was helpful! Good luck with your English studies! :)