This paper includes two interrelated studies. The first production study investigates the timing patterns of English as spoken by Chinese learners with different dialect backgrounds. The second comprehension study explores native and non-native speakers' assessments of the intelligibility of Chinese-accented English, and examines the effects of the listeners' language backgrounds on their perceptions of Chinese-accented English. The results showed that the Hong Kong (HK) group performed better in unstressed syllable duration compared with the Taiwan (TW) and Beijing (BJ) groups. The results also revealed that all six listener groups achieved at least 78 % intelligibility, with the native speaker accent achieving the highest rating, followed by the HK, TW, and BJ accents. A shared first language (L1) background may have little or no impact on intelligibility. The speech properties might prevail over the shared L1 effect. All listeners perceived inappropriate word-stress shift and consonant cluster simplifications to be the most unintelligible features.