| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | a couple [prep] years back | 30 |
|
| 2 | [art] couple [prep] years back | 30 |
|
| 3 | a couple [prep] years back | 30 |
|
| 4 | [art] couple [prep] years back | 30 |
|
| 5 | couple [prep] years back [conj] | 5 |
|
