| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | had [verb] into | 1720 |
|
| 2 | had [to-vb] into | 122 |
|
| 3 | [verb] to look into | 91 |
|
| 4 | had to look [prep] | 90 |
|
| 5 | had to look [prep] | 90 |
|
| 6 | [vb past] to look into | 34 |
|
| 7 | had look into | 22 |
|
| 8 | have to look into | 17 |
|
| 9 | had to look into | 6 |
|
