| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | a long period of time | 102 |
|
| 2 | a short period of time | 50 |
|
| 3 | a considerable period of time | 20 |
|
| 4 | a certain period of time | 19 |
|
| 5 | a fixed period of time | 18 |
|
| 6 | a limited period of time | 18 |
|
| 7 | a given period of time | 14 |
|
| 8 | a prolonged period of time | 11 |
|
| 9 | a reasonable period of time | 10 |
|
| 10 | a specified period of time | 9 |
|
| 11 | a particular period of time | 7 |
|
| 12 | a specific period of time | 5 |
|
