| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have been [vb pp] for [det] years | 70 |
|
| 2 | have been [vb pp] [prep] many years | 62 |
|
| 3 | has been [vb pp] [prep] [det] years | 37 |
|
| 4 | have been [vb pp] [prep] [det] years | 21 |
|
| 5 | had been [vb pp] [prep] [det] years | 18 |
|
| 6 | have been [vb pp] [prep] some years | 15 |
|
| 7 | have been known [prep] [det] years | 15 |
|
| 8 | have been used [prep] [det] years | 12 |
|
| 9 | have been [vb pp] over [det] years | 11 |
|
| 10 | have been [vb pp] [prep] several years | 5 |
|
| 11 | have been established [prep] [det] years | 5 |
|
