我有好簡單既英文五明

It is just like when we say 3256 in English, we say three thousand two hundred fifty six. We dont say three thousands two hundreds fifty six.

It does not mean we never say "thousands/hundreds/millions". Here is an example for you. There are thousands of people there.

用million而唔用millions係因為million係呢度係adj., 而非名詞(noun)用.