| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [adj] period of [noun] | 384 |
|
| 2 | [prep] a long [noun] of [noun] | 346 |
|
| 3 | [prep] a long [noun sg] of [noun] | 318 |
|
| 4 | [prep] [art] long period of [noun] | 136 |
|
| 5 | [prep] [art] long period of [noun] | 136 |
|
| 6 | [prep] a long period [prep] [noun] | 134 |
|
| 7 | [prep] a long period [prep] [noun] | 134 |
|
| 8 | [prep] a long period of [noun] | 127 |
|
| 9 | [prep] a long period of [noun] | 127 |
|
| 10 | [prep] a long period of [noun] | 127 |
|
