Let's evaluate each sentence for correctness:

1. **Anna makes yoga every morning**
**Incorrect** - The correct sentence should be: "Anna does yoga every morning."

2. **Can your brother play the piano?**
**Correct** - This sentence is grammatically correct.

3. **Adam can do pizza - it's very nice**
**Incorrect** - The correct sentence should be: "Adam can make pizza - it's very nice."

4. **Our baby sister can't ride a bike**
**Correct** - This sentence is grammatically correct.

5. **We do Karate on tuesday**
**Incorrect** - The correct sentence should be: "We do karate on Tuesday." (Note the capitalization of "Tuesday" and "karate" should not be capitalized unless it is part of a proper noun.)

6. **Can you play a skateboard?**
**Incorrect** - The correct sentence should be: "Can you ride a skateboard?"

So, the corrected sentences are:

1. Anna does yoga every morning.
2. Can your brother play the piano?
3. Adam can make pizza - it's very nice.
4. Our baby sister can't ride a bike.
5. We do karate on Tuesday.
6. Can you ride a skateboard?