The advantages and disadvantages of wider or narrower definitions of pidginization and pidgin are reviewed to determine the differences between pidgins and naturalistically learned second languages (L2s). It is argued that a wider definition is preferred because it avoids problematic counterexamples and captures generalizations that allow us to view the difference between naturalistic L2 varieties and pidgins as one of degree, not of type. In first language (L1) acquisition, Bates and Goodman (1999) showed the link between the development of vocabulary and grammar and argued that this may be explained by, among other things, logical and perceptual bootstrapping. It is suggested that these types of bootstrapping are also relevant for explaining the pace of grammar development in pidgins and naturalistic L2 varieties. The tense-aspect system of a Spanish variety spoken by a Chinese immigrant in Spain is examined in detail. The data, taken from a 90-minute interview that yielded 602 tokens, reveal several clear traits of the informant's verbal system: (a) All nonfinite, imperfective verb forms (gerunds) correspond exclusively to Vendlerian activities; (b) all but three of the perfective nonfinite forms (past participles) correspond to telic verbs or predicates; and (c) 81% of the stative verbs appear in the third-person-singular present form. The sensitivity to aspectual distinctions in the informant's variety of Spanish is not addressed by logical and perceptual bootstrapping. Furthermore, although this sensitivity can be partially explained by language-specific considerations (i.e., transfer from Mandarin), such an explanation does not speak to precise form–function mappings found, which are best accounted for by appealing to the Primacy of Aspect and Distributional Bias hypotheses (Andersen, 1993; Andersen & Shirai, 1996).