| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] concentrate on | 379 |
|
| 2 | [conj] [modal v] concentrate | 16 |
|
| 3 | [conj] [modal v] on | 15 |
|
| 4 | [conj] concentrate on | 10 |
|
