How can I know wether 'mich' and 'dich' should be in accusative or dative?
- Hast du DIR gestern den neuen film gesehen?
- Ich wasche MICH.
Why is the first one in DATIVE and the second one in ACCUSATIVE?
How can I know wether 'mich' and 'dich' should be in accusative or dative?
Why is the first one in DATIVE and the second one in ACCUSATIVE?
Hast du dir gestern den neuen Film angesehen?
The verb ansehen takes an accusative object, which is the person or thing watched. Here, that's den neuen Film.
The pronoun dir is an addition, it's not required by ansehen. If you use it, it has to be dative because it's the person or thing who receives something – the impression from the movie.
Ich wasche mich.
This one is very simple. The verb waschen takes an accusative object which is the person or thing washed. In this case, yourself.
BUT, some cases are tricky:
Ich wasche mir die Hände.
Clearly, you are washing your own hands. But why is it mir, not mich? Because again, die Hände is the thing washed, and mir is a person who receives something - a hand wash in this case. You can wrap you mind around this with the following example:
Ich wasche dir die Hände.
Now it's the other person who receives the hand wash.