| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have been used for | 195 |
|
| 2 | [vb -s] been used for | 69 |
|
| 3 | has been used for | 62 |
|
| 4 | [vb base] been used for | 54 |
|
| 5 | have been used for | 53 |
|
| 6 | had been used for | 36 |
|
| 7 | [vb past] been used for | 36 |
|
| 8 | have been used for | 23 |
|
| 9 | [vb infin] been used for | 23 |
|
| 10 | [to-vb] been used for | 10 |
|
| 11 | to have been used for | 10 |
|
| 12 | 's been used for | 7 |
|
