| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] [vb infin] for a [adj] | 260 |
|
| 2 | [vb infin] for a [adj] period | 19 |
|
| 3 | [modal v] [vb infin] for a period | 9 |
|
| 4 | [modal v] [vb infin] a [adj] period | 7 |
|
