| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [adj] period [modal v] | 19 |
|
| 2 | [prep] a [adj] period [modal v] | 19 |
|
| 3 | over a [adj] [noun sg] [modal v] | 15 |
|
| 4 | over a [adj] [noun] [modal v] | 15 |
|
| 5 | over [art] [adj] period [modal v] | 13 |
|
| 6 | over [art] [adj] period [modal v] | 13 |
|
| 7 | over a [adj] period [modal v] | 10 |
|
| 8 | over a [adj] period [modal v] | 10 |
|
| 9 | over a [adj] period [modal v] | 10 |
|
