Homophones. Specifically, pear, pare, and pair. See, the other day I bought four pears, one each of four varieties. So, that's two pairs of pears, or, if you will, a pair of a pair of pears. Now, just a moment ago, I was cutting out a soft spot from one of the pears with--what else?--my paring knife. So I was paring one of the pears from the pair of pair of pears.
This is why foreigners hate America. When they were kids their teachers forced them to learn English, thus sowing (not sewing) the seeds (not cedes) of their (not there and certainly not they're) great (not grate) pique (not peek and not peak either).