"Soon, I will work a Russian teacher at a college, but I also want to work as an English teacher. I hope my dreams come true some day!" "There are twenty minutes left until the end of the lesson." "What plants do you grow in your garden," or possibly, "What plants are you growing in your garden," depending on if the person you're addressing is currently gardening, or if they just happen to do so in general. If they're currently gardening, the second one will work, as it's in present tense. "Tonight we are throwing a party for John." You don't need "the sake of," as you can just say "for John," as it's a party for John. I changed "organizing" to "throwing," to make it sound more natural, but in this context, they mean the same, and either is fine. Like I said, "throwing" just sounds more natural. Or even "having," as in, "We are having a party for John." The last one is a little trickier. I think maybe, "Today, Tom scored a two in mathematics." I think this is the best possible way to convey it? I hope this helps! Overall, most of the sentences were nearly completely correct, with just a few small adjustments needing to be made. Not too bad at all! :)

i think that the folowing sentences are more correct : Soon I will work as a Russian teacher at the college but I also want to work as an English teacher, I hope my dreams will come true one-day. There are just twenty minutes to the end of the lesson. What plants do you grow at your garden? or (what are the plants that you cultivate in your garden?) Tonight, we are organizing a party for the sake of John. or (we are organizing a party for the sake of John Tonight) Today, Tom got two on mathematics.