This study analyzes the usage of 'V-yoo to omou' in an e-mail task given to 30 native speakers and 90 learners of Japanese. The e-mail task was to reply to a request to bring something to a picnic. It was found that Japanese language learners never used 'V-yoo to omou' despite having learned it, while it was a common choice of Japanese native speakers. 'V-yoo to omou' was used in this task to let the other person make the final decision, but learners did not understand this nuance. In conclusion, we found that we need to reconsider how 'V-yoo to omou' is taught.