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Conjunctive (connecting) adverbs connect the ideas expressed in different clauses or sentences. Some of the most common conjunctive adverbs: accordingly, also, anyhow, furthermore, however, moreover, otherwise, still, therefore.
Use of conjunctive adverb between two independent clauses requires a semicolon before the adverb and comma after it.
Ex: I want to sleep; therefore, I should go to be.
If conjunctive adverb is used at the beginning of a sentence, a comma is used to set it off. (Note that the period takes the place of a semicolon.)
Ex: The day was over. Therefore, I went to sleep.
If conjunctive adverb is placed within a clause, commas are used to set it off.
Ex: The day is over. I will, therefore, go to sleep.