| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | difficult to think of [adj] | 11 |
|
| 2 | difficult to think [prep] [det] | 6 |
|
| 3 | difficult to think [prep] [adj] | 5 |
|
| 4 | difficult to think [prep] any | 5 |
|
| 5 | difficult to think [prep] any | 5 |
|
