Everyone has a bad memory, so don't put too much pressure on yourself. Pay attention to combining work and rest. This memory will gradually improve. Or maybe your memory method is not good enough. Associative memory is the best way to learn English, from which simple rules can be found. If the sentence is too long, simplify it first and divide it into predicate and object. Then add words such as attributes and adverbials as appropriate. Those fixed short sentences will be remembered much faster as long as they are similar. If you remember a word, remember it by pronunciation. Even if you don't remember it clearly, you can remember it almost without forgetting it several times. English words have prefixes and suffixes and have fixed special meanings. In short, you can have a rest when you should.