20.3 active, passive Current readability formulas (1) base / are basedpurely on what (2) considers / is considered difficult fora native English speaker. They (3) fail / are failed to take into account problems that may (4) encounter / be encountered by nonnatives. One thousand five hundred PhD students from ten countries (5) asked / were asked to evaluate the difficulty of five technical texts from their discipline written by native English speakers. Three key difficulties) identi fi ed / were identified bi : unfamiliar vocabulary typically Anglo-Saxon words, unfamiliar cultural references, and the use of humor. The paper (7) also proposes / is also proposed anew approach to assessing the level of readability of texts to account for such difficulties. are based 2. is considered 3. fail 4. be encountered 5. were asked 6. were identified. proposes