助動詞（じょどうし、jodoushi）
- auxiliary verb

The Japanese word 助動詞 （じょどうし） means "auxiliary verb" or "helping verb." In Japanese grammar, 助動詞 are words that attach to the end of verbs, adjectives, or other words to add grammatical meaning, such as tense, aspect, modality, or politeness. They don't have meaning on their own but function to modify the meaning of the main word. They always follow the main verb, adjective, or another word. They often inflect, meaning they change form to indicate tense, mood, or other grammatical features.

⚫︎ 食べられる Translation: can eat ⚫︎ 食べた Translation: ate ⚫︎ 食べたい Translation: want to eat

助動詞 are essential for constructing grammatically correct and nuanced Japanese sentences. They are used extensively in everyday conversation and written Japanese. They add important contextual information that would be missing without them. Mastering 助動詞 is key to achieving fluency in Japanese. They are combined with verb stems, adjective stems, or other words to create specific grammatical meanings.

⚫︎ The word 助動詞 is typically written in kanji 助動詞, with the reading written in hiragana （じょどうし）. ⚫︎ There is only one way to write the word. ⚫︎ There are no variations in the okurigana.

There are no direct synonyms for 助動詞. The term is specific to the grammatical function. However, the term "auxiliary verb" is a synonym in English.

There are no direct antonyms for 助動詞. It is a functional grammatical term.

私は明日、学校に行かないです。 ・Translation: I will not go to school tomorrow. ・Explanation: The ない here is a negative 助動詞, which negates the verb 行く (go).

彼は本を読みたいと言った。 ・Translation: He said that he wants to read a book. ・Explanation: たい is a 助動詞 that expresses the speaker's desire. It is attached to the stem of the verb 読む (read).

The word 助動詞 is composed of three kanji: 助（じょ, help), 動（どう, move/verb), and 詞（し, word). This breakdown illustrates the function of 助動詞 – they help or assist the main verb to provide additional meaning or information. Therefore, the word is a direct description of what the words do.