Questions & Answers about Jetzt kauft er ein Buch.
Why is the word order Jetzt kauft er instead of "Jetzt er kauft"?
This is because of the "verb second" rule in German. In a standard main sentence, the verb must always be in the second position. Since the time word Jetzt (now) takes up the first spot, the verb kauft has to come next. That pushes the subject er (he) into the third spot.
Why does the verb kauft end with a -t?
The verb ending changes to match the subject, which is er (he). For regular verbs, when the subject is er, sie (she), or es (it), you take the dictionary form of the verb (kaufen), remove the -en, and add a -t.
The translation says "is buying", but where is the word for "is" in the German sentence?
German doesn't have a continuous "is doing" tense like English does. The single word kauft can mean either "buys" or "is buying". You just use the standard present tense, and the rest of the sentence (like Jetzt) makes the timing clear.
Why is it ein Buch and not eine Buch?
In German, the word for "a" changes depending on the grammatical gender of the noun. Buch (book) is a neuter word. For neuter words, the word for "a" is ein. You would use eine if the word were feminine.