If it's hard to remember which is which, maybe they should be different words.

Like "Customer validation" and "Verification against the spec"

Like "sympathy" and "empathy". I finally heard a mnemonic but if I need a mnemonic maybe it's a sign that the words are just too hard to understand

I just don't bother to shorten it...

- Did we correctly understand and build what the customer asked for

- Did the customer actually ask for what would solve the problem they are trying to solve

The second one is very important to ask early on, and _not_ asking it can cause a lot of wasted time. When I'm in a position to comment on whether I think someone fits the requirements of a senior developer, whether or not they ask that question plays directly into it.

Etymology to the rescue. "Valid" and "value" share a root, and so do "verify" and "verity." You validate something to see if it has value, meaning it works and is fit for purpose. You verify it to check that it is true and meets its specifications. Does that help? :)