A sentence is a group of words that make complete sense. The constituents of a sentence include a subject and a verb.
SIMPLE SENTENCE: A simple sentence is a sentence with only one clause; which is also known as the principal clause.
Different ways to structure a simple sentence:
Single subject + single verb: Maria is dancing.
Compound subject + single verb: Janet and David are dancing.
Single subject + compound verb: Frank is singing and dancing.
COMPOUND SENTENCE: A compound sentence consists of two independent clauses joined by a comma and a coordinating adjective/a semicolon/ semicolon with a conjunctive adverb. A compound sentence has two parts. Both the parts have subject and verb.
E.g.: Mrs. Potts reads her book every day, and then she knits.
COMPLEX SENTENCE: A sentence with one independent clause and at least one dependent clause is called a complex sentence.
E.g.: A poor child who is hungry would never pass up a piece of bread.
PHRASE: A phrase is a group of words which makes sense, but not complete sense. It cannot make a statement as it does not have either subject or predicate. It contains no finite verb. It can be further categorized into noun phrase, adjective phrase, adverbial phrase, adjective phrase, prepositional phrase and conjunctional phrase.
CLAUSE: A clause is a larger word group that includes a little more information. A clause contains a subject and a predicate. A clause may be either a sentence (an independent clause) or a sentence-like construction within another sentence (a dependent clause). All clauses in English have at least two parts: a noun phrase and a verb phrase.
Clauses can be divided into two parts:
INDEPENDENT CLAUSE: An independent clause is a group of words containing a subject and a predicate. By itself, an independent clause is a simple sentence because it expresses a complete thought. So it can stand alone as a sentence.
DEPENDENT CLAUSE: A group of words that has both a subject and a verb but cannot stand alone as a sentence is known as a dependent clause or subordinate clause. Dependent clauses add additional information to the main clauses, but they do not necessarily provide complete thought by themselves. A dependent clause usually starts with a word that makes the clause unable to stand alone.
The dependent clauses can further be divided into three types: adverb clauses, adjective clauses and noun clauses.
An adverb clause is a dependent clause used as an adverb within a sentence to indicate time, place, condition, contrast, concession, reason, purpose, result, etc.
An adjective clause is a dependent clause used as an adjective within a sentence. An adjective clause usually begins with a relative pronoun (which, that, who, whom, whose) or a relative adverb (where, when, why).
A noun clause is a dependent clause that functions as a noun (i.e. as a subject, object, or complement) within a sentence. It is also known as a nominal clause.