This study sets out to examine the pragmatic competence of Cantonese adult learners of English possessing different levels of proficiency when performing the speech act of requesting for a formal purpose in writing. Pragmatic judgment - one of the two aspects of pragmatic competence - was examined by studying the most proficient group (i.e., native Cantonese-speaking EFL teachers at university), whereas pragmatic performance - the other aspect of pragmatic competence - was examined by studying the two weaker groups (i.e., university students at two language proficient levels). Both pragmatic judgment and pragmatic performance were examined by investigating the same four dependent variables (i.e., politeness, directness, formality and amount of information). Teacher data, collected through a Pragmatic Judgment Questionnaire completed and returned by sixteen EFL teachers (eight native Cantonese speakers and eight native English speakers) and by means of individual interviews, were analyzed quantitatively for responses to twelve questions and qualitatively for responses to an additional two questions. Student data, consisting of both experimental and authentic letters and e-mails, were analyzed quantitatively. -- Main research findings suggest: *It is possible for very proficient NNSs of English, (i.e., the EFL teachers in this study), to achieve native-like pragmatic judgments in most aspects, except for their views on several pragmatic considerations (i.e., "unnaturally polite" expressions, usefulness of "negative" words, supportive moves not to be used and writing plans preferred). *As the English proficiency of L2 learners improves from Grade E to Grade A/B (as determined by the Hong Kong A-level Examinations in the subject "Use of English"), their pragmatic performance shows improvement. -- For pedagogical reasons, a qualitative analysis was conducted for Questions 1 and 2 in order to generate examples of "unnaturally polite"/ "polite" / "impolite" expressions and to provide examples of inappropriate supportive moves in relation to three writing topics.