Put 'how' at the beginning of a question when you want to ask what way or by what means something is done, or what state or condition something is in.
In fact, you already know three 'how' questions: "How are you?", "How old are you?", and "How do you do?".
The first kind of 'how' question follows the same pattern as 'how are you?': How + 'be' + noun?
- How is the new teacher?
- How is your work?
- How was school today?
The second kind of 'how' question follows the same pattern as 'how old are you?': How + adjective/adverb? We use it to ask about the degree or extent of something.
- My grandfather is old.
- How old?
- He's 100 years old!
We can use 'how' with adjectives and adverbs:
- How many? (to ask about the quantity of countable nouns)
- How much? (to ask about the quantity or price of uncountable nouns)
- How often? (to ask about the frequency)
- How far? (to ask about the distance)
