| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb -s] [been] used for many years | 7 |
|
| 2 | [vb -s] [been] used for [det] years | 7 |
|
| 3 | [vb -s] been used for [adj] years | 7 |
|
| 4 | has [been] used for [adj] years | 7 |
|
| 5 | [vb -s] [been] used for many years | 7 |
|
