Error analysis of English prepositions used by low-proficiency Thai EFL university students

This research aimed to find out the English prepositions that cause major problems for Thai EFL university students and to investigate which source of errors (i.e., interlingual errors and intralingual errors) affected Thai EFL students’ English preposition use the most. The sample group of this research consisted of 53 first-year-students, not majoring in English, from a public university in Kachanaburi Province. The research instrument was a 22-question test with four choices focusing on the use of zero and 10 English prepositions (i.e., in, to, of, at, with, for, by, about, on, and from). The data were analyzed by the error analysis approach and the sources of errors were classified. Ten participants were randomly selected to obtain qualitative data. The findings confirmed that the English preposition error was one of the problematic issues for low-proficiency Thai EFL university learners. The addition of unnecessary prepositions was the most frequent classification of error found, while of, to, from, in, and about were the top five misused English prepositions. The findings revealed that the learners' native language, Thai (L1), exhibited both positive and negative transfer when they employed English prepositions. Notably, intralingual errors had a more pronounced impact on the usage of English prepositions compared to interlingual errors.