Because learning English is extremely popular in non-native English speaking countries, developing modern assisted-learning schemes that facilitate effective English learning is a critical issue in English-language education. Vocabulary learning is vital within English learning because vocabulary comprises the basic building blocks of English sentences. Therefore, numerous studies have attempted to increase the efficiency and performance of learning English vocabulary. "The situational learning approach" proposed that "context" is an important consideration in the language learning process and can enhance learner learning interest and efficiency. Restated, meaningful vocabulary learning occurs only when the learning process is integrated with social, cultural and life contexts. With the rapid development of context-awareness techniques, the development of context-aware mobile learning systems, which can support learners in learning without constraints of time or place via mobile devices and associate learning activities with real learning environment, enables the conduct of a novel context-aware ubiquitous learning mode to enhance English vocabulary learning. Accordingly, this study proposes a personalised context-aware ubiquitous learning system (PCULS) for learning English vocabulary based on learner location as detected by wireless positioning techniques, learning time, individual English vocabulary abilities and leisure time, enabling learners to adapt their learning content to effectively support English vocabulary learning in a school environment. Experimental results indicated that the accuracy of the employed wireless positioning scheme is over 92%, which is sufficient to help learners detect their locations. Additionally, the PCULS has been successfully implemented on PDA devices in a school environment to support effective situational English vocabulary learning. Experimental result indicates that the learning performance of learners who used personalised English vocabulary learning systems with context awareness (i.e. PCULS) was superior to learners who used personalised English vocabulary learning systems without context awareness. (Contains 5 tables and 5 figures.)