level1 -- unit 3

频率副词

1. never
2. sometimes
3. usually
4. always

never 从不

sometimes 有时

usually 通常

always 总是

频率排名(从最不到最经常)：

never > sometimes > usually > always

1. 频率副词位于实义动词之前
2. 频率副词不影响动词的单复数形式（意思还是受主语的人称和数量影响）
   比如，Leo sometimes works on weekends
   works还是要保持第三人称的单数形式，加个s
3. 频率副词位于be动词之后
4. 频率副词位于助动词之后，位于实义动词之前。
5. 频率副词位于情态动词之后。

操练

1. my girlfriend never smiles
2. she sometimes cries suddenly
3. my dog usually goes out for a walk with it's dog after dinner
4. they always get home late
5. my colleague is always later for work
6. i don't usually tell that to my boss
7. my boss can always works for 23 hours per day