It's a sentence fragment.
i started a group about food
a group of words that make a sentence
a sentence that is made up of different words combined to make a complete thought.
Add the necessary words to complete the sentence and make it clear and concise.
They make up a sentence.
If you are asking whether the words "Is this a question" make a complete sentence, yes-- but not a declarative sentence. They make a question, and they need a question mark at the end. A declarative sentence is just a statement of fact: "Yes, this is a complete sentence." But a question is where you ask someone about something: "Do you have any questions to ask me?"
It depends on the context. Something as simple as 'He killed the cat.' - is a complete sentence.
A complete thought does have a verb; but having a verb does not make a group of words a complete thought. A complete thought must have at least one verb, but a complete thought can also have several verbs.An incomplete though that does have a verb is called a clause.A group of words becomes a sentence when it is a complete thought. Some examples:The cookies that Mary made were passed out to the class. (The dependent clause 'that Mary made' has a subject and a verb, but it is an incomplete thought.)I watched TV while Mary washed the dishes, packed the lunches, and made some coffee. (There are four verbs in the sentence, but the sentence is a single complete thought.)
Using the word "then" at the beginning of a sentence is not incorrect. However, it does not make a sentence complete. A complete sentence must have, at a minimum, a subject and a verb. "Then" is neither of those.
My best friend (All the words in the subject make up the complete subject.)