12 Július - (just a note, in Hungary, we follow YY-MM-DD, but it's spelled right.)

He shouted something, but I didn’t hear. - Kiáltott valamit, de nem hallottam. (you forgot to put them in past tense, what you wrote literally means, he shouts/ he is shouting, but i cannot hear / i am deaf.)

I had a dream. - Egy álmom volt. / Volt egy álmom. (word order in Hungarian is highly flexible, however the rule puts the most important part of the sentence in the front. So Egy álmom volt stresses that you had just one, not two or six or thirteen and a half. I assume the original sentence is just telling about you having a dream in general, so the past equivalent of "to be", the "volt" should come first.)

I decided to cook the eggs. - Úgy döntöttem tojásokat főzök. / tojást főzök. ("úgy döntöttem" is a more common way to translate your sentence, "döntés" means decision, "dönteni" is to decide, also to "knock something on it's side" but obviously that is not the context here. Also while both plural and singular version of the sentence is correct, I would say the singular is more common to say in this case, since the language does not use plural in a lot of cases where English would require it. This is also true when you're trying to say things like "three eggs" - we just say "három tojás" and not "három tojások".)

This is a useful practice. - Ez egy hasznos gyakorlás. (The use of "to be" is not required here, some would say you could lose "egy" as well, because it will sound more natural, so "Ez hasznos gyakorlás" is also good, if not better.

This chair is uncomfortable. - Еz а szék kényelmetlen. (Same thing about the "van", also we use "a" - and sometimes said just "e", often in literature -  if the word following starts with a consonant, and use "ez/az" if it starts with a vowel.)

Unfortunately, that time will be inconvenient. - Sajnos az idő nem lesz alkalmas. (Time means "idő", óra is "hour / clock". Kényelmetlen is more like "uncomfortable" in a way if you're sitting on a poorly made chair.)


Are you allowed to go on a break? - Elengedtek szünetre? (Literally: did they let you go on a break? - engedni is to let / to release, and here the "on a break" is quite literally used with the "ra/re" suffix, what you normally use for "to go on top of" something.)
I drove the car to the store. - A kocsit vezettem a boltba. - Good! This is a grammatically correct sentence. I'm just listing "Kocsival mentem a boltba" as an alternative, also a common way to say the same thing, literally "I went to the store with a car".


He was an average student. A átlagos tanuló volt. - Közepes is more like "average sized", the word is derived from "közép" which is "center". In the statistical meaning you would like to use "átlagos", where "átlag" means the mathematical average value. Iskolás is more like "schoolboy/schoolgirl", i would say "tanuló" or "diák". Tanuló literally means "learner". If you're talking about university / college level education, hallgató is the word for students, meaning "listener (of lectures)".


Was that the correct choice? - Helyes választás volt? (választ - he/she chooses, választás as literally "choosing" is the term you are looking for. In political contexts "Választás" also means "election".)

Was the exercise useful? - Hasznos feladat volt? perfect.

I was sure of the answer. - A biztos voltam a valászban. (literally: i was sure in the answer, it's just the way we say it.)

He decided to go to the movies. - Úgy döntött moziba megy. (Again, "döntött" is the translation for decided which is more fitting in these cases. But "elhatározta, hogy moziba megy" is also optional, if you'd like to stick with the word "határozni".)

Your cat is very shy. - A macskád nagyon szégyenlős. very good!

He is standing in the shade. - Az árnyékban áll. (with your original sentence you wrote he is standing in his own shadow. Both árny and árnyék is used for shadow, however árny is shadow of a figure, often having an ominous meaning, while árnyék is the shade of non-living objects, often used to hide under, like trees buildings or umbrellas. Also you unwillingly added the possessive participant for 3rd person, or whatever it's called, "a/á" in this case. So if i wanna say my shadow, i'd say árnyékom. your shadow - árnyékod. his/her shadow - árnyéka... etc. and if you stick another suffix after that, it will change from "a" to "á": in his shadow - árnyékában. Same goes with "árny"->"árnyában".

Did you pay the fare? - Viteldíjat fizettél? (no need for "a", and a minor spelling mistake, othewise a good sentence!)

They got lost in the mountains. - Eltévedtek a hegyekben. you should put "getting lost" in past tense but othwerwise it' absolutely perfect!

good job!