Questions & Answers about Ich kaufe keinem Kind ein Handy.
Why is it keinem Kind instead of kein Kind?
In this sentence, the child is the receiver of the action, meaning the person you are buying the phone for. In German, the receiver takes the dative case. Because Kind is a neuter noun, the negative article kein must change to keinem to show this dative role.
Why does the child come before the cell phone in the sentence?
When a German sentence has both a dative receiver (the child) and an accusative thing being acted upon (the cell phone), the dative object usually comes first. That is why keinem Kind is placed before ein Handy.
Why doesn't ein Handy change its ending like keinem did?
The cell phone is the direct object because it is the actual thing being bought, so it takes the accusative case. Since Handy is a neuter noun, its indefinite article in the accusative case is just ein, which looks exactly the same as its basic dictionary form.
The English translation says "not buying a child", but doesn't keinem mean "no"?
Yes, literally this translates to "I buy no child a cell phone." When negating a noun that would normally use "a" or "an", German prefers using the negative article kein instead of saying "not a" (nicht ein).