1044: Utterances Oct 18, 2017
It is often taught that every sentence must have a subject and a verb, thanks in part to Aristotle. This is true in English, in passive constructions too, but this does not mean that this is the manner in which English speakers always or even mostly speak. A general set of examples for this that requires little context is with answering questions, such as
Speaker 1: "what do you want?"
Speaker 2: "pizza"
which has no verb and, debatably, no subject, but is still pretty clear. It is also possible to replace phrases like "do you want to..." with "wanna..." which does not have subject, less (though still somewhat) debatably than before. These are not sentences though, but utterances, and while they may not be preferred for formal writing, they are absolutely fine in normal speech, especially because they can rely more on context, which is usually harder to gain from writing.
Speaker 1: "what do you want?"
Speaker 2: "pizza"
which has no verb and, debatably, no subject, but is still pretty clear. It is also possible to replace phrases like "do you want to..." with "wanna..." which does not have subject, less (though still somewhat) debatably than before. These are not sentences though, but utterances, and while they may not be preferred for formal writing, they are absolutely fine in normal speech, especially because they can rely more on context, which is usually harder to gain from writing.