| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | period [prep] [adv] [adj] years | 32 |
|
| 2 | period [prep] [adv] [adj] years | 32 |
|
| 3 | period of [adv] [adj] years | 32 |
|
| 4 | period of [adv] [adj] years | 32 |
|
| 5 | period [prep] [adv] [adj] years | 32 |
|
| 6 | period [prep] [adv] [num] years | 31 |
|
| 7 | period [prep] about [adj] years | 15 |
|
| 8 | period [prep] about [adj] years | 15 |
|
| 9 | period [prep] nearly [adj] years | 5 |
|
| 10 | period [prep] nearly [adj] years | 5 |
|
| 11 | period [prep] [adv] twenty years | 5 |
|
| 12 | period [prep] [adv] twenty years | 5 |
|
