Nouns are generally easier to learn than verbs (e.g., Bornstein, 2005;Bornstein et al., 2004;Gentner, 1982;Maguire, Hirsh-Pasek, & Golinkoff, 2006). Yet, verbs appear in children's earliest vocabularies, creating a seeming paradox. This paper examines one hypothesis about the difference between noun and verb acquisition. Perhaps the advantage nouns have is not a function of grammatical form class but rather related to a word's imageability. Here, word imageability ratings and form class (nouns and verbs) were correlated with age of acquisition according to the MacArthur-Bates Communicative Development Inventory (CDI) (Fenson et al., 1994). CDI age of acquisition was negatively correlated with words' imageability ratings. Further, a word's imageability contributes to the variance of the word's age of acquisition above and beyond form class, suggesting that at the beginning of word learning, imageability might be a driving factor in word learning.Nouns tend to appear before verbs (Gentner, 1982) and to dominate English-speaking children's early lexicons (e.g., Fenson et al., 1994;Goldin-Meadow, Seligman, & Gelman, 1976). This finding has been replicated across the globe, with languages like German, Mandarin, Kaluli, Japanese, Turkish (Gentner, 1982), Spanish (Jackson-Maldonado, Thal, Marchman, Bates, & Gutierrez-Clellen, 1993), Italian (Caselli et al., 1995), French (Bassano, 2000;Parisse & Le Normand, 2000;Poulin-Dubois, Graham, & Sippola, 1995) and others (Bornstein, 2005;Bornstein et al., 2004; but see Tardif, Wellman, Fung, Liu, & Fang, 2005). Even in the laboratory, novel nouns are learned more quickly and easily than novel verbs (e.g., Childers & Tomasello, 2002;Golinkoff, Hirsh-Pasek, Bailey, & Wenger, 1992;Golinkoff, Jacquet, Hirsh-Pasek, & Nandakumar, 1996), a result also found in Japanese where verbs often appear in privileged, sentence-final positions (Imai, Haryu, & Okada, 2005) and in Chinese where verbs can appear in isolation Imai et al., 2008).Explanations for the preponderance of nouns in early vocabularies come in three forms. First, Kersten and Smith (2002) and Echols and Marti (2004) suggest an attentional explanation: Children preferentially attend to objects and prefer to map new names to objects rather than to the actions in which the objects are engaged. Only when children know the names of the objects will they go on to learn the names of the actions. Second, the disparity is based in perception: While objects are often stable in time and space, actions are fleeting and dynamic and unfold in time and space. Extracting a categorical representation (or the "verbal essence," Golinkoff et al., 2002) is more difficult than perceiving the object categories that nouns label (see also . Learning the name of an action requires that children perceptually abstract the invariants of the action (e.g., running) across multiple exemplars that show wide variation. For example, a toddler, Grandpa, and a dog all run, but do so in very different ways (Golinkoff et al., 2002). A final explanation h...