1.sometimes (频率副词)，意为“有时”, 多用于一般现在时，可位于句首，句中或句末，提问要用 how often。
例如：How often do you write to your friend? I sometimes write to my friend.
2. sometime（副词），意为“某时”，表示不确定的时间，一般用于将来时态，对它的疑问词要用 when.
例如：When will you go to Beijing next month? I will go to Beijing sometime next month.
3. some times （名词短语），表示“几次，几倍”， 对它的提问要用 how many times
例如：1)How many times have you read the book? I have read the book some times.
2)Our school is some times larger than theirs.
4. some time （名词短语），意为“一些时间”，表示一段时间，句中的谓语动词要用延续性动词，提问要用 how long.
例如：How long will you stay here? I will stay here for some time.
5. 习题巩固
1) Will you stay in Shanghai for _______? Yes, I will.
2) _____ she goes home by bike and _____ on foot.
3) The building was built ______ before 1988.
4) After ______, Amy came back from Beijing.
5) He has been told not to watch TV too much _______.
答案：1. some time 2. Sometimes, sometimes 3. sometime 4. some time 5. some times
