1. Ein buch, accusative, direct object of "kaufen". The book is being bought, so it must be in accusative and book is neuter, therefore it needs 0 ending for ein words. 2. If you want to say named "Bobbie oder die...", you can use "namens" after a comma. Otherwise, you'll need a relative clause. "....a book THAT is called..." "...ein Buch, das heißt" 3. Unlike Spanish, but like english, adjectives always come before the noun they describe and therefore have to take an adjective ending. Since this word is preceded by an "ein" word, you will need a "strong" or "primary" case ending. For feminine accusative, that ending is "-e" 4. The USA is plural, the United StateS. and "in" is a two-way preposition, so you have to think about whether there is motion or relocation involved. In this case, you're just saying that he lived there, not that he moving there, so it's dative-stative; not accusative-movative. So the dative plural ending for "der/die/das" words is (-en), giving you "den". 5. Does this sentence make sentence in English? "I have only read two pages, but many vocabulary to learn. If it doesn't make sense in English, it probably doesn't make sense in German either. The sooner you learn relative classes, the better. But first, you need to learn cases. 6. like and as are not prepositions in English nor German. I look like HE. (not him). You should work as hard as SHE. (not her). So after "wie" and "als", you need the nominative case.