Definition: A word or group of words that expresses a complete thought. In traditional grammar, a sentence must include at least a subject (a noun or something that substitutes for a noun) and a predicate (which has to include a verb). A sentence can express a statement, ask a question or give a command.
In Spanish, it is very common for the subject to not be directly stated, although it is implied by the conjugation of the verb. For example, the word hablamos, which means "we speak," can be a complete sentence. The subject of the sentence is not directly stated, although it is implied to be nosotros, which means "we."
In English, the subject can be similarly implied, although only when the verb is in the imperative mood, that is, when the sentence is a command. For example, the command "speak" is a complete sentence; the listener can infer that the subject is "you."
Exclamations, such as "ouch!" in English or "¡ay!" in Spanish, can express a complete thought, although they generally are not considered to be sentences.
Also known as: oración, frase in Spanish
Examples in Spanish: El cielo es azul. ¿Cuál es el significado de la vida? ¡Cállate! (These sentences make a statement, ask a question and give a command, respectively.)
Examples in English: The sky is blue. What is the meaning of life? Shut up!