Upon examining the results, we found that "unknown words" existed in the candidate sentences. The first sentence in Table 13 contains one of these words ( see Table 13 ). The word のん " (noN) " has almost no meaning. However, this word was accepted by the system because the valency patterns can be applied even in this case. In other words, this sentence containing this word was not interpreted as ungrammatical.
| 母が私に新しいのんをくれた |
| `` Hahaga watashini atarashiinoNwo kureta. '' |
| `The mother gave me the newer None' |
We think that the overall recognition rate can be further improved by using the valency patterns that can take into account these unknown words.