| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | may have been a [adj] [noun] | 66 |
|
| 2 | [modal v] have been a [adj] factor | 9 |
|
| 3 | may have been [art] [adj] factor | 7 |
|
| 4 | may have been [art] [adj] factor | 7 |
|
| 5 | may have been a [adj] factor | 6 |
|
| 6 | may have be a [adj] factor | 5 |
|
| 7 | may have [be] a [adj] factor | 5 |
|
| 8 | may have [been] a [adj] factor | 5 |
|
| 9 | may [vb infin] been a [adj] factor | 5 |
|
| 10 | may [verb] been a [adj] factor | 5 |
|
| 11 | may have been a [adj] factor | 5 |
|
