| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb past] a period of | 67 |
|
| 2 | followed a period [prep] | 12 |
|
| 3 | entered a period [prep] | 8 |
|
| 4 | [vb past] a period in | 7 |
|
| 5 | had a period [prep] | 6 |
|
