These differences in the use of preposition between Thai and English may result in the incorrect use of English preposition for Thai students. Moreover, contrary to prepositions of time, place, and direction, prepositions after some verbs and adjectives are rather arbitrary and cannot be explained by explicit rules. The source of input can add more difficulty to ESL/EFL learners due to the language variation of English native speakers to whom the learners are exposed (Celce-Murcia & LarsenFreeman, 1999). For example, an English native speaker may say “go out to lunch,” while another may say “go out for lunch.”