B1. A Sentence is a group of words that is complete in itself, usually containing a subject and predicate, conveying a statement, instruction, question, exclamation, or command, and consisting of a main clause and starts with a capital letter in writing, and finishes with a period '.'.

B2. A simple sentence has only one clause. (e.g. The children were laughing.)

B3. A compound sentence has two or more clauses. (e.g. (We stayed behind) and (finished the job))

B4. The clauses in a compound sentence are joined by coordinating conjunctions: and, but, or, nor, so, then, yet. (e.g. John shouted and everybody waved.)

B5. A complex sentence has a main clause and one or more adverbial clauses. Adverbial clauses usually come after the main clause. (e.g. Her father died (main clause) when (subordinating conjunction) she was very young (adverbial clause))

B6. Some subordinate clauses can come in front of the main clause. (e.g. Although (subordinating conjunction) some snakes are dangerous (adverbial clause) most of them are harmless (main clause))

B7. A sentence can contain both subordinate and coordinate clauses. (e.g. Although (subordinating conjunction) she has always lived in Korea (adverbial clause) she speaks fluent English (main clause) because (subordinating conjunction) her mother was English (adverbial clause) and (coordinating conjunction) her father was Irish. (adverbial clause))

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