don't you think?

Use this question to ask for agreement from a listener. People use this expression when:

• they're making a suggestion:
  

  You should ask the professor for help, don't you think?

• they want to state their opinion, but they don't feel confident enough to just directly say it
• they want the listeners to feel included in the statement
  

  Wow. I love this place. It's great, don't you think?

• they want the listener to admit that something is true:
  

  You're too old for that, don't you think?

get started on (something)

The phrase "get started" simply means "start".

You use "get started on ___" to talk about work that needs to be done:

Do you want me to get started on the salad?

A: Can you pull together a list of all of our clients in that region for the past two years?

B: Of course. I'll get started on that right away!

Just use "start" to talk about ongoing actions:

I need to start exercising.

(do something) sooner rather than later

This phrase means to do something soon, and not wait. You use it like this:

I think we should talk to an accountant sooner rather than later.

If you're going to break it off with him, you ought to do it sooner rather than later.