to begin with

1. From the outset; initially; in or at the very beginning. I never would have bought this car to begin with if I'd known there weren't airbags. You should have said you were feeling ill to begin with! I wouldn't have given you such a hard time if I'd known.

2. As the first of a given set of points (e.g., in an argument). Why am I quitting? Well, to begin with, I haven't been paid for overtime in nearly a year, and I just don't feel valued as an employee in general. There are a lot of problems with your paper. To begin with, you just seem to move from point to point at random.

to beˈgin with

1 at first: I found it tiring to begin with but I soon got used to it. ♢ We’ll go slowly to begin with.
2 used to introduce the first point you want to make: ‘What was it you didn’t like?’ ‘Well, to begin with, our room was far too small.’