5. A dictionary registration method comprising: first inputting including inputting a first input text in a first language; extracting, when the first input text includes an unregistered text that is not registered as a first text in the first language in dictionary information stored in a first storing unit, in which the first text is associated with a second text that is a translation of the first text into a second language; determining a part of speech of the unregistered text and, in accordance with the part of speech, determining whether to convert a pronunciation of the unregistered text into an expression in the second language; converting the pronunciation of the unregistered text into the expression in the second language when it is determined to convert the pronunciation; second inputting including inputting a second input text in the first language, the second input text expressing the unregistered text with a text being different from the unregistered text when it is determined not to convert the pronunciation; translating the second input text into the second language; and registering the unregistered text in association with the second input text translated into the second language on the dictionary information, or registering the unregistered text in association with the text which is the expression in the second language converted from the pronunciation of the unregistered text, on the dictionary information.
5. A dictionary registration method comprising: first inputting including inputting a first input text in a first language; extracting, when the first input text includes an unregistered text that is not registered as a first text in the first language in dictionary information stored in a first storing unit, in which the first text is associated with a second text that is a translation of the first text into a second language; determining a part of speech of the unregistered text and, in accordance with the part of speech, determining whether to convert a pronunciation of the unregistered text into an expression in the second language; converting the pronunciation of the unregistered text into the expression in the second language when it is determined to convert the pronunciation; second inputting including inputting a second input text in the first language, the second input text expressing the unregistered text with a text being different from the unregistered text when it is determined not to convert the pronunciation; translating the second input text into the second language; and registering the unregistered text in association with the second input text translated into the second language on the dictionary information, or registering the unregistered text in association with the text which is the expression in the second language converted from the pronunciation of the unregistered text, on the dictionary information. 6. The method according to claim 5 , further comprising: storing first information in which the first text is associated with the part of speech of the first text; acquiring a part of speech corresponding to the unregistered text from the first information; and determining the part of speech acquired at the acquiring as a part of speech corresponding to the unregistered text.