| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a long period [conj] | 28 |
|
| 2 | over a long period [conj] | 16 |
|
| 3 | over a long period [conj] | 16 |
|
| 4 | [prep] a longer period [conj] | 15 |
|
| 5 | [prep] a long period [coord] | 14 |
|
| 6 | [prep] a long period and | 13 |
|
| 7 | [prep] a long period and | 13 |
|
| 8 | [prep] a long period [conj] | 13 |
|
| 9 | [prep] a long period than | 12 |
|
| 10 | [prep] a long period [subord] | 12 |
|
| 11 | [prep] a long period than | 12 |
|
| 12 | for a long period [conj] | 10 |
|
| 13 | for a long period [conj] | 10 |
|
