| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | for a long period [prep] [noun sg] | 19 |
|
| 2 | for a long period of [noun sg] | 17 |
|
| 3 | for a long period of [noun sg] | 17 |
|
| 4 | for a long period [prep] time | 14 |
|
