否定疑问式：can I not？／can't I？could I not？／couldn't I？等
表示许可的 can的其他形式可用 allow，be allowed 的相应形式代替。can 与不带 to 的不定式连用。
You can memorize words in an efficient way if you pronounce them reasonably. Say words correctly, and you will learn them easily. Correct pronunciation means correct spelling of the words. English spelling is not good to guide its pronunciation. But spelling and pronunciation have closed relationship. They match each other perfectly. Sometimes we can pronounce a word according to its spelling. English pronunciation can also guide its spelling. This is a two-way communication.
