Bloomfield and Hockett observe that not all languages have special completive interjections. Finnish does not generally answer yes-no questions with either adverbs or interjections but answers them with a repetition of the verb in the question, negating it if the answer is the negative. (This is an echo response.) The answer to "Tuletteko kaupungista?" ("Are you coming from town?") is the verb form itself, "Tulemme." ("We are coming.")
Negative questions are answered similarly. Negative answers are just the negated verb form. The answer to "Tunnetteko herra Lehdon?" ("Do you know Mr Lehto?") is "En tunne" ("I don't know.") or simply "En." ("I don't.").
However, Finnish also has particle words for "yes": "Kyllä" (formal) and "joo" (very colloquial). A yes-no question can be answered "yes" with either "kyllä" or "joo", which are not conjugated according to the person and plurality of the verb. "Ei", however, is always conjugated and means "no".