substitute
1.substitute用作不及物动词作“做代替者”解，是美国用法。例如：As Mr Sinclair was ill, Mr Cook substituted as our teacher of chemistry.
2.下面四句意思相同：
- We have to substitute tea for coffee.
- We have to substitute coffee by tea.
- We have to substitute coffee with tea.
- Tea has to substitute coffee.
第一句是正当的，其他三句都不算正当。substitute的正确意思是“把…用作代替者”，不是“把某人或某物代替（某人或某物）”或“代替（某人或某物）”。下面每组里的三句都不该说：
- He omitted of and substituted it by for.
He omitted of and substituted it wirh for.
He omitted of and made for substitute it. - Of was substituted by for (by him).
Of was substituted wirh for (by him).
Of was substituted by for.
第一组该改作He omitted of and substituted for (for it)，第二组该改作For was substituted for of.
