Why I have studied English for 12 years but my English is still poor

Maybe not strictly "necessary" but probably very helpful. People learn a language more quickly when they are immersed in it. Conversational English is relatively easy to pick up but the immense vocabulary can make reading difficult. Spelling is often irrational and pronunciation is irregular. What is your native language?

your spelling could use a little work...

1. I believe there are essentially four elements of language learning.

2. Reading, Writing, Speaking, and Listening.

3. Of those four elements, Reading and Listening are forms of input.

4. Of those four elements, Speaking and Writing are forms of output.

5. Input is learning to comprehend what your ears hear or what your eyes read.

6. Output is learning to vocalize what you want to say or learning to write what you want to say.

7. When having a conversation with someone, you are speaking. You are also listening. That is input and output occurring at the same time.

7. Is there an element that you are better at or worse at?