Two recent papers (de Villiers & Johnson, 2007; Johnson, de Villiers & Seymour, 2005) have claimed that children have difficulty with verbal "-s" until five- six-years-old. This contrasts with perceptual studies showing evidence for sensitivity to the grammatical properties of verbal "-s" as young as 1;4. These apparently conflicting findings can be reconciled by differentiating between early perceptual grammatical knowledge and later semantic comprehension. (Contains 1 footnote.)