When do writers need to use a conjunction? when they need to explain where something happened
when they need to be more specific about a noun
when they need to show what an action looked like
when they need to connect—or join—two ideas

when they need to connect—or join—two ideas

Explanation:

Writers need to use a conjunction in order to connect two ideas together. There are mainly four types of conjunctions: Coordinating conjunctions, Correlative conjunctions, Conjunctive Adverbs and Subordinating conjunctions.

Using these different conjunctions allow the writers' thoughts to be well-delivered and understood by the reader smoothly. It also allows him to create better sentences. It is important for the writer to know how to use these conjunctions properly in order to prevent incoherent sentences.

the answer is typhoon