fail
[误] Tom failed his exam.
[正] Tom failed in his exam.
[正] Tom failed to pass the exam.
[析] fail为不及物动词，其后可用in加名词，或直接接不定式。
family
[误] Im sorry I have to go. Toms families are waiting for me.
[误] Im sorry I have to go. Toms family is waiting for me.
[正] Im sorry I have to go. Toms family are waiting for me.
[析] family是集合名词，把它当作整体看它是单数，如看作家庭中的每个成员则为复数。如：Your family are very kind to me. My family is very large.
far
[误] My school is ten miles far from here.
[正] My school is ten miles away from here.
[析] far一般不与实际距离连用。
[误] Did you walk far?
Yes，I walked far.
[正] Did you walk far?
Yes, I walked a long way.
[析] 一般肯定句中不用far单独作状语，而用a long 组成的常用词组有：as far as. ①远至，一直到。如：He walked as far as the station. ②就而言。如：As far as he was concerned these books were very good. ③只要。如：I can help you as far as I can.? so for到目前为止。例：He is very well so far.
