| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | in a [noun] [prep] | 21392 |
|
| 2 | [prep] a letter [prep] | 696 |
|
| 3 | in [art] letter [prep] | 519 |
|
| 4 | in a letter [prep] | 469 |
|
