1. He likes eating some bread and eggs for breakfast. (remove the "s" after "bread" and add "egg" to make it singular)
2. How many biscuits do you eat every day? - One small package. (add "s" to "biscuit" to make it plural and change "do" to "does" for subject-verb agreement)
3. Why shouldn't you eat too much chocolate? - Because you can become overweight. (change "What" to "Why" for appropriate question word and use "become overweight" instead of "be too fat")
4. What would you like to drink, Quan? - Apple juice, please. (add "to" after "like" and add "please" at the end of the sentence)
5. My sister usually drinks three bottles of water every day. (change "bottle" to "bottles" for plural form)

1. He likes eating some breads and egg for breakfast.
=> 1. He likes eating some bread and eggs for breakfast. 
2. How many biscuit do you eat every day? - One small package.
2. How many biscuits do you eat every day? - One small package. 
3. What shouldn't you eat too much chocolate? - Because you can be too fat.
3. Why shouldn't you eat too much chocolate? - Because it can cause weight gain. 
4. What would you like drink, Quan? - Apple juice, please.
=> 4. What would you like to drink, Quan? - Apple juice, please. 
5. My sister usually drinks three bottle of water every day.
=> 5. My sister usually drinks three bottles of water every day.
 

1. He likes eating some bread and eggs for breakfast. 
2. How many biscuits do you eat every day? - One small package. 
3. Why shouldn't you eat too much chocolate? - Because it can cause weight gain. 
4. What would you like to drink, Quan? - Apple juice, please. 
5. My sister usually drinks three bottles of water every day