If you've ever seen Mythbusters, you know that all episodes contain at least one safety disclaimer. Having recently rewatched several episodes, I've noticed that some disclaimers have Adam saying, "Don't try this at home. We've got years of experience that keeps us safe."
That sounded a little funny to me, and I'm wondering whether that's grammatically correct. Shouldn't it be "years of experience that keep us safe"? Technically, it makes sense that it's the singular 'experience' that keeps the Mythbusters safe, but shouldn't the verb 'keep' be referring to the years of experience as a whole? I mean, it's the fact that they've got years, and not, say, minutes, that are keeping them safe. Right? Or is the sentence perfectly fine?
Update: I think part of the issue is the word 'experience' itself, which is singular regardless of how much there is of it. Words that come in discrete units (such as, say, 'blocks') are made plural when they're modified by multiple units ('5 blocks') — experience, however, remains singular. 'Much experience', 'experience', and 'no experience' are all singular.
Best Answer
I don't think you can categorically identify either version as "incorrect".
As OP says, superficially "We've got years of experience that keep us safe" seems correct, since the subject of the verb keep is the plural noun phrase years of experience.
But I personally have no problem parsing it as experience that keeps us safe. The fact that this experience is qualified by years of seems to me no different to if it had been qualified by plenty of, or a great deal of. It's the singular experience, not the plural years, that helps.
In short, both seem "defensible" to me, but I find the singular verb form flows better.