| | Re: "except" vs "except for"
I've never seen an explanation that holds up in terms of meaning difference when you're talking about excluding a specific instance from a general statement - eg :
I know nothing about it except/except for what you've told me
Everyone was dressed formally except/ except for John.
- for me they're more or less interchangeable.
However, only except (or rather except that) can be followed by a clause expressing a reason :
We would have gone out except (that) it was raining.