1. Conjunctions are words that link words, phrases, and clauses together. They allow for more complex sentences to be formed rather than a series of short, choppy sentences.
2. There are three main types of conjunctions: coordinating conjunctions join elements of equal grammatical rank, correlative conjunctions work in pairs, and subordinating conjunctions join independent and dependent clauses.
3. Exercises are provided to help understand the different conjunctions, including filling in sentences with the correct conjunction based on meaning and structure.