| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb pp] several years | 62 |
|
| 2 | [vb past] several years | 39 |
|
| 3 | take several years | 36 |
|
| 4 | spend several years | 28 |
|
| 5 | [v-ing] several years | 21 |
|
| 6 | [vb infin] several years | 21 |
|
| 7 | take several years | 13 |
|
| 8 | spent several years | 12 |
|
| 9 | spent several years | 12 |
|
| 10 | [to-vb] several years | 11 |
|
| 11 | last several years | 11 |
|
| 12 | [vb base] several years | 8 |
|
| 13 | taken several years | 7 |
|
| 14 | [vb -s] several years | 7 |
|
| 15 | follow several years | 7 |
|
| 16 | lasting several years | 6 |
|
| 17 | have several years | 6 |
|
| 18 | took several years | 5 |
|
| 19 | following several years | 5 |
|
| 20 | take several years | 5 |
|
