Otherwise is a transitional adverb. It does not connect two clauses. It merely shows how the idea expressed by one clause is related to what has already been said.
Otherwise is usually preceded by a full stop or a semicolon. It is sometimes followed by a comma.
Otherwise means ‘if not’.
- You must work hard; otherwise you will fail. (If you do not work hard, you will fail.)
- We must hurry; otherwise we will miss the train.
Otherwise is mainly used to talk about negative outcomes.
- I think it will soon stop raining; otherwise, we will have to cancel the trip.
- I hope he mends his ways; otherwise, he will be sacked.
Otherwise can be used to suggest that something is true.
- Of course she is interested in him. Otherwise, she wouldn’t get upset when I told her that he was dating another woman.
- She must be very intelligent. Otherwise, she couldn’t have solved that puzzle.
Otherwise can be used to suggest that something is true except for the fact you have just mentioned.
- She was tired but was otherwise fine.
- We had some difficulty finding his address, but otherwise everything was fine.