You use otherwise after mentioning a situation or telling someone to do something, in order to say what the result or consequence would be if the situation did not exist or the person did not do as you say.
Make a note of the questions you want to ask; you will invariably forget some of them otherwise.
把你想问的问题记下来;否则你准会忘记其中几个。
I'm lucky that I'm interested in school work, otherwise I'd go crazy.
幸好我对学校作业还感兴趣,不然会疯的。
You use otherwise before stating the general condition or quality of something, when you are also mentioning an exception to this general condition or quality.
The decorations for the games have lent a splash of colour to an otherwise drab city.
运动会的装饰为这个平淡无味的城市增添了一抹色彩。
You use otherwise to refer in a general way to actions or situations that are very different from, or the opposite to, your main statement.
Take approximately 60 mg up to four times a day, unless advised otherwise by a doctor.
每天最多服四次,每次约60毫克,或遵医嘱。
There is no way anything would ever happen between us, and believe me I've tried to convince myself otherwise.
相信我,我曾试图说服自己还有希望,但是我们之间真的不可能了。
You use otherwise to indicate that other ways of doing something are possible in addition to the way already mentioned.
The studio could punish its players by keeping them out of work, and otherwise controlling their lives.
电影公司通过禁演来惩罚他们,并采用其他方法控制他们的生活。
or otherwise , and otherwise
You use or otherwise or and otherwise to mention something that is not the thing just referred to or is the opposite of that thing.
It was for the police to assess the validity or otherwise of the evidence.
应由警方来评定证据是否有效。