Student or Learner
Could you help me with the underlined part?
A: I feed your dog blueberries, and he likes them. Do you know he likes fruit?
B: He'll eat anything that's not nailed down.
I know what "nail down " means when it is used as verb, but I don't know its usage in this context.
Please help me with this phrase, thank you.
If something is nailed down, you can't pick it up.
It's a somewhat common idiom (anything/everything that's not nailed down) to mean "just about everything." It's similar to "everything but the kitchen sink."
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.