*used to ask or talk about the way in which something happens or is done:
How do you spell your name?
How can I help you?
I’d like to help in some way, but I’m not sure how.
He explained how the system worked.
We both used to work at the airport – that’s how we met.
*used to ask or talk about the amount, size, degree etc of something:
How big is the state of Louisiana?
How many kids do they have now?
How long have you been learning English?
Do you know how old it is?
How much does this book cost?
*used after certain adjectives or verbs to refer to an event or situation:
It’s amazing how they’ve managed to get everything finished so quickly.
I remember how she always used to have fresh flowers in the house.
*used to emphasize the quality you are mentioning:
How great to see you here!
He was impressed at how well she could read.
How or what?
"How" is use what with look/feel/be like to ask for or give a description:
What does she look like?
✗Don’t say: How does she look like?
• You use what with think to ask or talk about someone's opinion:
What do you think of him?
✗Don't say: How do you think of him?
Another good thing to know is the expression: how on earth/in the world
"As" is used:
*when you are comparing two people, things, situations:
Tom’s not as old as you, is he?
an old woman with hair as white as snow
Some of the doctors are paid almost twice as much as the nurses.
* to say what job, duty, use, or appearance someone or something has:
As a parent, I feel that more should be done to protect our children.
A flat stone was used as a table.
Dad dressed up as Santa Claus.
I work as a teacher=I am a teacher
Be careful and don't mix it up with "like":
I work like a slave (I'm not a real slave, but my work is just as hard and difficult as slaves' work was.)
*As is used to say what someone thinks or says a person or thing is:
The problem is regarded as serious.
But: I didn't realize HOW serious the problem was