Question word: How, How many, How much, How often, How old

1. HOW ….?

2. How…?
 How = Procedure, in what way, or by what methods:
Q: How does he take photos?
A: He takes photos with his cell phone.

3. How many…?
 How many = Quantity of something (plural countable nouns):
Q: How many students are in the class right now?
A: 12.

4. How much…?
 How much = Price or the quantity of something (uncountable noun):
Q: How much is this jacket?
A: It´s USD 80.

5. How often…?
 How often = Ask about frequency that someone does something:
Q: How many do you go to the cinema?
A: I go to the cinema every weekend.

6. How old…?
 How old = Age:
Q: How old are you?
A: I´m 25 years old.