the non-independent clause because I have no friends is related to the non-independent clause I don't go out in I don't go out, because I have no friends. The whole clause complex is independent because it realises a statement. What is stated is the causal nexus between having no friend and not going out. When such a statement is acted out, the fact that the speaker doesn't go out is already established, therefore it cannot be stated. What is still open and under negotiation is the reason for that fact. The causal nexus is represented by the independent clause complex and not by the two interdependent clause simplexes. See also copula for the consequences of the verb to be on the theory of sentence structure. Classification By structure One traditional scheme for classifying English sentences is by clause structure, the number and types of clauses in the sentence with finite verbs. A simple sentence consists of a single independent clause with no dependent clauses. A compound sentence consists of multiple independent clauses with no dependent clauses. These clauses are joined together using conjunctions, punctuation, or both. A complex sentence consists of one independent clause and at least one dependent clause. A compound–complex sentence (or complex–compound sentence) consists of multiple independent clauses, at least one of which has at least one dependent clause. By function or speech act Sentences can also be classified based on the speech act which they perform. For instance, English sentence types can be described as follows: A declarative sentence typically makes an assertion or statement: "You are my friend." An interrogative sentence typically raises a question: "Are you my friend?" An imperative sentence typically makes a command: "Be my friend!" An exclamative sentence, sometimes called an exclamatory sentence, typically expresses an exclamation: "What a good friend you are!" The form (declarative, interrogative, imperative, or exclamative) and meaning (statement, question, command, or exclamation) of a sentence usually match, but not always. For instance, the interrogative sentence "Can you pass me the salt?" is not intended to express a question but rather to express a command. Likewise, the interrogative sentence "Can't you do anything right?" is not intended to express a question on the listener's ability, but rather to express a statement on the listener's lack of ability; see rhetorical question. Major and minor sentences A major sentence is a regular sentence; it has a subject and a