Verb conjugation of "tighten" in English

Yes, I speak a little bit of English. I'm just beginning to take English courses in private evening classes. Is your Spanish good? I will speak to you in Spanish and you teach me in English.
On the frozen lake, you can skate, but I would never dare it because it is far too dangerous. Who knows how thick the ice really is and how accurate the measurements are. It can break.
What problems did you have when you had to share your flat with your mates? Probably you were not used to it. We say that when we live close we usually discover many issues that were not known.