| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | could have [been] [verb] for | 69 |
|
| 2 | could have [been] [vb pp] for | 59 |
|
| 3 | could have [been] used [prep] | 23 |
|
| 4 | could have [been] used [prep] | 23 |
|
| 5 | [vb mod] have [been] used for | 15 |
|
| 6 | [modal v] have [been] used for | 15 |
|
| 7 | could have [be] used for | 6 |
|
| 8 | could have [been] use for | 6 |
|
| 9 | could [verb] [been] used for | 6 |
|
| 10 | could have [been] used for | 6 |
|
| 11 | could have [been] used for | 6 |
|
