"I need to buy a jacket."
Translation:Мне нужно купить куртку.
Why can't I write "Мне надо покупать куртку." What is the difference between курить and покупать?
Курить is a completely different verb meaning "to smoke", the verb you need is купить. Купить is perfective, покупать is imperfective. You're talking about a one-time completed action, the focus is on the result, not the process - you need to buy a coat, and then you have a coat and you're done. Using the imperfective would mean something like "I need to be buying a coat".
What's the difference between a coat and a jacket? These are interchangeable to me (except when jacket means the top half of a suit)
To me a jacket is much lighterweight - I wear a jacket when it's a bit chilly and a coat when there's snow on the ground. But then I call the top half of a suit a coat...
Many Russians don't feel any difference between two. The надо и нужно are often interchangeable. However if you're Russian and you're learning English you'll learn "have to" means надо whereas "need" means нужно.
Either works here. Надо is a bit more informal, I think. Надо does not decline and is generally only used with verbs. Нужно can be used with nouns, in which case it does decline to match the gender/number of the thing that is needed.
Why нужно and not нужна? Or does the -о not refer to куртка (female), but to мне?
In the sentence «мне нужно купить куртку» the subject is not a jacket, but "to buy a jacket". It's like "to buy a jacket is necessary to me"
For a noun or pronoun to be a grammatical subject, it would have to be in nominative case.
My mistake. Yes 'jacket' is a subject and nuzhno kupit' is a compound predicate.
Yeah, "куртка" in "Мне нужна куртка" is the subject.
I don't think "нужно купить куртку" would be considered a predicate, though, since "predicate" pretty much means "what's not the subject" (more specifically verb + complements: direct or indirect objects, predicate nouns or adjectives, etc).
My translation, keeping the grammatical logic of the Russian, would probably be "Buying a jacket is necessary for me." There, "Buying a jacket" is the subject. I don't know if it's common to think of "купить куртку" in the Russian sentence as a "субъект" or not, but in English it seems reasonable to think of it as the subject.
In Russian language, we call it «подлежащее». But I'm not sure if «купить куртку» can be officially named «подлежащее» or this sentence doesn't have any подлежащее. Maybe «нужно купить куртку» is «сказуемое» (predicate), but there is no «подлежащее».
But to explain the structure of the sentence, I think, it can be helpfull to say that «купить куртку» is similar to a subject.
Подлежащее отвечает на вопрос кто или что. Поэтому это будет "Покупка куртки".
Мне нужно купить куртку - члены предложения:
куртку "подлежащее" (что)
нужно купить "сказуемое" (что сделать) Нужно - категория состояния, часть сказуемого
мне дополнение (кому)