| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | a [adj] period [vb mod] [vb infin] | 15 |
|
| 2 | a [adj] period [modal v] [vb infin] | 12 |
|
| 3 | a long period [modal v] [vb infin] | 6 |
|
| 4 | a [adj] period may [vb infin] | 5 |
|
| 5 | a [adj] period may [vb infin] | 5 |
|
| 6 | a [adj] period will [vb infin] | 5 |
|
| 7 | a [adj] period will [vb infin] | 5 |
|
