| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | course is [prep] [num] years ' | 45 |
|
| 2 | course be [prep] [num] years ' | 45 |
|
| 3 | course be [prep] [num] years ' | 45 |
|
| 4 | course be of [num] years ' | 44 |
|
| 5 | course be of [num] years ' | 44 |
|
| 6 | course be [prep] three years ' | 24 |
|
| 7 | course be [prep] four years ' | 15 |
|
| 8 | course be [prep] two years ' | 6 |
|
