Find the mistakes in the following sentences and correct them

Find the mistakes in the following sentences and correct them
1. Ken studied for the test more hardly than John did.
Answer: _______________ => ______________
2. Today I feel badly than yesterday.
Answer: _______________ => ______________
3. My mom is clever than me.
Answer: _______________ => ______________
4. Today they play happier than they did yesterday.
Answer: _______________ => ______________