| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] [prep] 20 years ['s] [noun] | 6 |
|
| 2 | [verb] [prep] 20 year ' [noun] | 6 |
|
| 3 | [verb] [prep] 20 year ['s] [noun sg] | 6 |
|
| 4 | [vb pp] [prep] 20 year ['s] [noun] | 5 |
|
