I've decided revenge is a pitiful pursuita and a waste of my fleeting time, so...我已决定,复仇是一个悲哀的追求目标也不值得我花费宝贵的时间,所以

a waste of 浪费, 白费

That's simply a waste of time.

这根本是浪费时间。

It is a waste of time to listen to his insignificant talk.

听他那些废话纯属浪费时间。

But if you indeed plan on being part of this family,但如果你的确想成为这个家庭的一份子

plan on 打算

He refused to adopt the plan on the grounds of its high cost.

他拒绝采纳这个计划，原因是成本太高。

Don't plan on my going with you, for I expect to be busy this weekend.

不要以为我会陪你去，因为本周末我会很忙的。

part of一部分

The last part of the ascent is very steep.

最后一段上坡路很陡。