Sitting close to the laptop’s screen hurt your eyes.
Correct: Sitting close to the laptop’s screen hurts your eyes.

You can avoid many diseases by eat healthy food.
Correct: You can avoid many diseases by eating healthy food.

You look so bad! How’s wrong with you?
Correct: You look so bad! What's wrong with you?

Eating lots of fast food can make you fat or obesity.
Correct: Eating lots of fast food can make you fat or obese.