| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | how long [vb mod] [noun] | 16 |
|
| 2 | how long [modal v] [noun] | 16 |
|
| 3 | how long [modal v] [noun prp] | 7 |
|
| 4 | how long [modal v] [noun sg] | 6 |
|
| 5 | how long will [noun] | 5 |
|
| 6 | how long will [noun] | 5 |
|
