In conversation, people don't pay close attention to grammar, but writing is VERY different. Grammar is very important for writing, so writers need to learn a little about grammar.
Four important points:
1) Many English speakers (people in the US, Canada, the UK, Australia and New Zealand) don't like grammar and don't understand it. That is because many of their teachers didn't teach REAL English grammar. Grammar makes some people feel stupid ("I only speak English, but my teacher says my grammar is wrong. I must be stupid!")
2) Real English grammar (based on Modern English) is different from old-style school grammar (based on Ancient Latin). Latin grammar is difficult and it makes many people feel stupid. Real grammar DOESN'T make you feel stupid. A very good place to learn Modern English grammar is the free Internet Grammar of English, prepared by University College, London. This was published about 15 years ago.
You can also find the Internet Grammar of English in a Chinese version:
If you have a cell phone, you can try the Interactive Grammar of English, which is more modern. The free version, iGE Lite is available for Android (Google Play Store) and Apple (iTunes Store) phones:
3) After you understand a little REAL grammar, you will start to see "old friends" (familiar grammar patterns) when you read stories. Be sure to read read lots and lots of interesting, easy stories. This is the best way to learn grammar "in your bones" (= you know it so well that it feels natural).
4) After you see the same few grammar patterns many times, you will start to use them because the grammar is "in your bones" (滾瓜爛熟). That is why good writers need to read a lot.
