| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a period which | 12 |
|
| 2 | [prep] a period which | 12 |
|
| 3 | a [adj] period which | 8 |
|
| 4 | a [adj] period which | 7 |
|
| 5 | a [noun] period which | 6 |
|
| 6 | a [noun sg] period which | 6 |
|
| 7 | a period [prep] which | 79 |
|
| 8 | a period [prep] which | 79 |
|
| 9 | a period in which | 47 |
|
| 10 | a period in which | 47 |
|
| 11 | a period during which | 23 |
|
| 12 | a period during which | 23 |
|
| 13 | a period which [verb] | 9 |
|
| 14 | a period which [modal v] | 7 |
|
| 15 | a period which [vb mod] | 7 |
|
| 16 | a period which [vb past] | 7 |
|
