"I do not want to read this long book."
Translation:Я не хочу читать эту длинную книгу.
When you speak about a book as a physical object, «то́лстая кни́га» sounds better. When you speak about a book as a literary work (i.e. not a thing with cover and pages, but the text), then «дли́нная кни́га» works, too.
We have the two verbs here: хоте́ть ‘to want’ and чита́ть ‘to read’. Хоте́ть is the main action, and чита́ть explains what is not wanted.
In Russian, we use the personal forms for the main verb (я хочу́ ‘I want’, ты хо́чешь ‘you want’, она́ хо́чет ‘she wants’, etc.), and use the unchanged infinitive for the additional verbs (so, чита́ть leaves unchanged).
So, you only change the main verb (хоте́ть ‘to want’) to match the subject of the sentence, and leave the second verb unchanged:
- я хочу́ чита́ть ‘I want to read’,
- ты хо́чешь чита́ть ‘you want to read’ (singular, informal),
- она́ хо́чет чита́ть ‘she wants to read’, он хо́чет чита́ть ‘he wants to read’,
- мы хоти́м чита́ть ‘we want to read’,
- вы хоти́те чита́ть ‘you want to read’ (plural or formal),
- они́ хотя́т чита́ть ‘they want to read’.
(This makes Russian different from some other Slavic languages. For example, Macedonian would change both verbs: «јас сакам да читам» ‘I want to read’, «ти сакаш да читаш» ‘you want to read’, «она сака да чита» ‘she wants to read’.)
I also would like to know this. It seems to me that the perfect form of the verb, «прочитать», would work better here (not saying the imperfect form is wrong). Surely, if there is any dread about reading a long book, it is because you have to read the whole thing, no? I think both should be accepted.