Examples of using "もう子供じゃないんだ。" in a sentence and their english translations:
- I'm not a kid anymore.
- I am not a kid anymore.
You are no longer a child.
- I am no longer a child.
- I'm not a kid anymore.
- I am not a kid anymore.
Since you are no longer a child, you are to take care of yourself.
You're not a kid anymore, you can take care of yourself.