I can't agree with you more, but one thing in learning a language that I want to emphasize the most is to go all out.

1) "I can't agree with you more" - usage. What and who are you agreeing with?
2) "That" - stylistic. It emphasizes the thing you haven't mentioned yet.

I often see many English learners who are Chinese in some learning groups or learning apps always writing and speaking in Chinese, which makes me very confused: do they really want to learn English?

"Who are chinese" - stylistic. Even though you are presumably talking about native Chinese speakers, it sounds better to say so upfront.

Maybe they a're just forhaving fun, or at least, they are non't serious learners.

Instead, "...or at least, they aren't being serious" - stylistic, but it would be better since the first part of the sentence is "they're just having fun."

Let me takuse myself as an example: if no people are surarounded by me, I listen to English and write down what I ha've heard, as well as reading and speaking the language.

"Let me use myself" vs. "Take me as an example" - stylistic

Since I decided to learn English wellseriously in September 2019, I have never wasted a minute.

1) Do you mean you started learning English at the end of September 2019? If so, "well into"
2) Do you mean you wanted to learn English as well as physically possible and that was in September 2019? If so, I think it's better to replace "well" with "seriously"

As long asWhenever I have time, I will do those things I have told the've said above.

1) "As long as" - stylistic, but sounds like you are saying you are dying

I can't agree with you more, but the one thing I want to emphasize in learning a language I want to emphasize the most isis the need to go all out.

Maybe they are learning just for fun, or at least, they are not serious learners.

So apart from patience, you have to go all out,. You should takinge every minute you get to study and immerse yourself completely in English.

Let me take myself as an example: if no people are surarounded by me, I listen to English and write down what I have heard, as well as. I practice reading and speaking as well.

If there are people around me, I write in English and post it ion some apps so that native English speakers can correct theme.

them didn't really refer back to anything, so I chose 'me'.

If you wanted to say sentences than you would need to reference elsewhere in the sentence.

As long as I have time, I will do those things I have told thesaid above.