turns over but won't start

I have my brother's 5 speed beretta while my car is getting fixed. It ran fine on Saturday night, then went to start it Sunday morning and it was turning over but not starting. It comes close to starting sometimes, but won't catch. It got colder than it's been (Minnesota), and we tried jump starting it (even though we were pretty sure that wasn't the problem).

Any ideas? I'm not going to put a bunch of $ into it since it's not my car, and my brother is out of town until Saturday, but it would be helpful to at least know what's wrong with it. I'm not sure what year the car is, but i'm sure it's more than 6 years old.

Most common items, crank sensor failure, igniton module failure, fuel pump failure, clogged fuel filter, bad tank sending unit(could be out of fuel but showing fuel in tank). Other reasons too. Hard to say, would advise you to specify year and type of motor etc. as that always helps people here give you advice.

cold weather needs heat for fuel lines not to freeze ..

also make sure tank is at least 1/2 to be safe...

check spark , and then check fuel pressure...

check all fuses too

i would check the timing belt