| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] [det] a period of | 9 |
|
| 2 | [prep] [det] a period of | 9 |
|
| 3 | [det] be a period of | 14 |
|
| 4 | [det] [be] a period of | 14 |
|
| 5 | [det] [prep] a period of | 11 |
|
| 6 | [det] [prep] a period of | 11 |
|
| 7 | [det] was a period of | 10 |
|
| 8 | [det] [was/were] a period of | 10 |
|
| 9 | [det] a [adj] period of | 10 |
|
| 10 | [det] a [adj] period of | 10 |
|
| 11 | [det] a long period of | 5 |
|
| 12 | [det] a long period of | 5 |
|
| 13 | [det] a period of [noun sg] | 9 |
|
| 14 | [det] a period of [noun] | 9 |
|
| 15 | [det] a period of time | 5 |
|
| 16 | [det] a period of time | 5 |
|
