Arabic verbs, like the verbs in other Semitic languages, and the entire vocabulary in those languages, are based on a set of two to five consonants called a root. The root communicates the basic meaning of the verb, e.g. ك-ت-ب k-t-b 'write', ق-ر-ء q-r-ʾ 'read', ء-ك-ل ʾ-k-l 'eat'. Changes to the vowels in between the consonants, along with prefixes or suffixes, specify grammatical functions such as person, gender, number, tense, mood, and voice.