| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [noun] [modal v] | 2545 |
|
| 2 | [prep] a [noun sg] [modal v] | 2506 |
|
| 3 | [prep] [art] period [modal v] | 25 |
|
| 4 | [prep] [art] period [modal v] | 25 |
|
| 5 | [prep] a period [modal v] | 5 |
|
| 6 | [prep] a period [modal v] | 5 |
|
