| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be of [adj] years ' duration | 48 |
|
| 2 | [be] of [adj] years ' duration | 48 |
|
| 3 | [be] of [num] years ' duration | 48 |
|
| 4 | [be] of [adj] years ' duration | 48 |
|
| 5 | [is] of [adj] years ' duration | 44 |
|
| 6 | is of [adj] years ' duration | 44 |
|
| 7 | [be] of three years ' duration | 24 |
|
| 8 | [be] of three years ' duration | 24 |
|
| 9 | [be] of four years ' duration | 17 |
|
| 10 | [be] of four years ' duration | 17 |
|
| 11 | [be] of two years ' duration | 7 |
|
| 12 | [be] of two years ' duration | 7 |
|
