occasion

1.occasion前面用on。例如：I met some strangers on that occasion.

2.on occasion作“偶尔地”解。例如：I call on him on occasion.注意不用复数形式occasions。

3.have occasion to...（不定式）作“有…的必要”解。例如：I had occasion to spend a night at a temple some years ago.下面几点该注意：

（1）这种用法不作“有…的机会”解。

（2）occasion前面没有an或the。

（3）说“没有…的必要”可以说have no occasion to..., have little occasion to...或not have any occasion to...。例如：I have no（或little）occasion to see him these days.和I do not have any occasion to see him these days.

比较下面两句：

• I have no occasion to see him.（我不必要看见他。）
• I have no opportunity（或chance）to see（或of seeing）him.（我没有机会看见他。）
• I have no occasion of seeing him是不成立的。

4.take occasion to...（不定式）作“趁着机会而…”解。例如：I took occasion to tell him about my work.下面两点该注意：

（1）occasion前面没有an或the。

（2）“不趁着机会而…”该说not take occasion to...，不可说take no occasion to...或take little occasion to...或not take any occasion to...，如可以说I did not take occasion to tell him about my work，不可说I took no（或little）occasion to tell him about my work或I did not take any occasion to tell him about my work。

5.occasion用作动词可以有双宾语。例如：His long silence occasions me great anxiety.但现在用occasion不及用cause普通。