Yes, you can use correlative conjunctions in both speech and writing. They can help you to organize your ideas and express yourself more clearly in a variety of contexts.
Some common mistakes to avoid include using correlative conjunctions to connect subjects, failing to use both parts of the conjunction, and using the wrong conjunction to express the intended relationship between two parts of the sentence.
You can use correlative conjunctions to connect two clauses that express alternatives, two negative options, two positive options, or two options with added emphasis. Be sure to use the appropriate conjunction for the relationship you want to express.
Correlative conjunctions are important because they can help to make your writing more clear and concise. By using these conjunctions, you can connect ideas and show the relationship between different parts of your sentence.