..., therefore...

Or

..., and therefore...

Bir çeviriye bakın

These are nearly the same.
I think 'and therefore' is mostly said when there is some disagreement or just tension about what should happen or did happen.
In that situation, 'therefore' can be used but 'and therefore' is for emphasis.
- A: Why don't we have any eggs? B: Well, I'm the only one who gets groceries and I had to work late all week and therefore we don't have any.
- Sam: Why do I have to sit in the front row of the class? I don't like that. Teacher: You aren't doing your best work and therefore we need to help you pay better attention.
- We can't get one. We really don't have enough room yet and you need to feed and walk it every day. I think you'll get tired of the dog after a couple of months and therefore it's not a good idea for you or the dog right now.