Meuter and Allport (1999) demonstrated greater RT (response time) costs for bilinguals to switch to their first language (L1) from their second language (L2) relative to switching to L2 from L1. Here, analyses of digit naming and simple arithmetic (from 2+2 to 9+9 and from 2x2 to 9x9) by Chinese-English bilinguals demonstrated that these asymmetrical language switching costs can vary with stimulus format (Arabic or Mandarin numerals), and that the asymmetry is observed both with direct retrieval (e.g. naming the digit "8") and indirect retrieval from the lexicon (e.g. answering "2+6"). Inhibitory processes in language selection entail format- and task-specific skills.