II 副 certainly; surely; necessarily: |
| 星期天一定来啊。 Be sure to come on Sunday. |
| 告诉他一定不能说出去。 Tell him that under no circumstances is he to let it out. |
| 我们的目的一定要达到。 我们的目的一定能够达到。 Our goal must be attained. Our goal can unquestionably be attained. |
| 他一定是被什么要紧事拖住了。 He must have been held up by some urgent business. |
| 可以口头汇报,不一定要写成书面材料。 An oral report will do; it isn't necessary to put it in writing. |