Why was the sentence verb+ing?

[nhatruc30]

Dear all.

I read a paragraph and and saw words, the underlined ones in the sentence below, that confused me. I thought of it why the author didn't use analyze, stop, try, and look instead of analyzing , looking , trying and stopping
If someone knows, please give me help
I'm expecting from you.
Your sincerely,
Truc


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Here is the content of paragraph:

What is necessary to learn English well?


The fact is, if you want to learn to speak English well, you must change your life. Here are some examples of things you will have to do:

· read a book in English for an hour every day, analyzing the grammar in sentences and looking up words in an English dictionary


· listen to an audiobook or other recording in English, stopping it frequently, trying to understand what is being said, and trying to imitate the speaker's pronunciation

[Tdol]

When do you think the person should analyse the language and look up the words- while reading or afterwards?