| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | a [adj] period of | 889 |
|
| 2 | a [adj] period of | 781 |
|
| 3 | a long period of | 183 |
|
| 4 | an [adj] period of | 108 |
|
| 5 | a short period of | 84 |
|
| 6 | a brief period of | 33 |
|
| 7 | a prolonged period of | 30 |
|
| 8 | a fixed period of | 27 |
|
| 9 | a considerable period of | 23 |
|
| 10 | a initial period of | 22 |
|
| 11 | a certain period of | 22 |
|
| 12 | a continuous period of | 19 |
|
| 13 | a lengthy period of | 19 |
|
| 14 | a limited period of | 19 |
|
| 15 | a extended period of | 18 |
|
| 16 | a reasonable period of | 16 |
|
| 17 | a specified period of | 15 |
|
| 18 | a particular period of | 15 |
|
| 19 | a given period of | 14 |
|
| 20 | a maximum period of | 13 |
|
| 21 | a minimum period of | 11 |
|
| 22 | a transitional period of | 10 |
|
| 23 | a new period of | 9 |
|
| 24 | a sustained period of | 8 |
|
| 25 | a rough period of | 7 |
|
| 26 | a mean period of | 6 |
|
| 27 | a specific period of | 5 |
|
| 28 | a experimental period of | 5 |
|
| 29 | a deferred period of | 5 |
|
| 30 | a agreed period of | 5 |
|
