Minh enjoys collecting stamps and coins. = Minh is a stamp and coin collector.

My mom bought a bike and a motorbike yesterday. = My mom bought a bike and a motorbike yesterday. (This sentence is fine as is.)

Nobody told me about the change of the meeting. = I did not know about the change of the meeting.

Does your dad play badminton everyday? = Your dad plays badminton everyday, doesn't he? (Or: Is your dad a badminton player?)

There are twenty-five students in my class. = My class has twenty-five students.

Don't swim in that lake, or you will have skin rashes. = If you swim in that lake, you will have skin rashes. (Or: If you don't swim in that lake, you won't get skin rashes.)