| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] [art] period he [modal v] | 5 |
|
| 2 | [prep] [art] period he [modal v] | 5 |
|
| 3 | [art] period he [modal v] [vb infin] | 5 |
|
| 4 | [art] period he [modal v] [verb] | 5 |
|
| 5 | [art] period he [modal v] serve | 5 |
|
| 6 | [art] period he [modal v] serve | 5 |
|
