"What" is used to ask a question about a specific thing or situation. It is used to seek information or clarification. For example:

What is your name?
What time is it?
What did you do yesterday?

The word "what" comes from the Old Engpsh word "hwæt," which means "what."

"How" is used to ask about the way something is done or to seek information about a process. It can also be used to ask about the condition or quapty of something. For example:

How do you spell your name?
How was your vacation?
How cold is it outside?

The word "how" comes from the Old Engpsh word "hū," which means "how."

"Which" is used to ask about a choice or to seek information about a specific person or thing. It is used to present options and allow someone to choose. For example:

Which movie do you want to watch?
Which of these two books do you prefer?
Which one is yours?

The word "which" comes from the Old Engpsh word "hwilc," which means "which."

Here are some examples in Engpsh with Chinese translations:

What's your name? 你叫什么名字？
How do you spell your name? 你的名字怎么拼写？
Which of these books do you want to read? 你想读哪一本书？