These questions are all about English learning-oral English, grammar and so on. Therefore, the answer should be based on the meaning of the sentence and give appropriate methods.
Answer in English:
1. He can't pronounce it correctly. -His pronunciation is not accurate. He can practice by listening to tapes. He can practice by listening to tapes.
He made grammatical mistakes-he made grammatical mistakes. Solution: He can practice by making sentences. And ask his English teacher questions. He can strengthen his grammar ability by making sentences and asking questions to the English teacher.
He forgot many new words-he forgot many new words. Solution: He can practice by making.
Vocabulary card, he can help remember words by making vocabulary cards.
He can't read the words in the magazine-he can't read the meaning of the words in the magazine. Solution: He can look them up in the dictionary. He can look up these words in the dictionary.
He can't pronounce some words-he can't pronounce some words. Solution: He can practice by reading new words every day. Listen to the tape. He can practice by reading new words and listening to tapes every day.
FYI
I didn't translate the above translation exactly according to the literal meaning, but it didn't affect my understanding. These are just some solutions, there are others. I just give a few examples here, I hope you can understand.