| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [adj] period [modal v] | 15 |
|
| 2 | [prep] a [adj] period [modal v] | 15 |
|
| 3 | over a [adj] period [modal v] | 7 |
|
| 4 | over a [adj] period [modal v] | 7 |
|
| 5 | a [adj] period [pron] [modal v] | 9 |
|
| 6 | a [adj] period [modal v] [vb infin] | 12 |
|
| 7 | a [adj] period [modal v] [verb] | 12 |
|
| 8 | a [adj] period [modal v] be | 10 |
|
| 9 | a [adj] period [modal v] [be] | 10 |
|
| 10 | a [adj] period [modal v] be | 10 |
|
| 11 | a [adj] period [modal v] [be] | 10 |
|
