Hiragana
As an example of how the grammatical endings are used we can take the verb “to eat” which is食べる (taberu).  Here the main part of the word “eat” (pronounced “ta” in this case) is the kanji 食.  The other two syllables: “be-ru” are in hiragana (べる).  To say “I ate” or “you ate” etc. you would say “tabemashita”, written食べました (“be-ma-shi-ta” is written in hiragana).