This study examines and compares the use of [ðIs] and [ðæt] by native speakers of English (NS’s) and non-native speakers of English (NNS’s) in a deictic study. The study examines traditional definitions of this and that found in dictionaries as well as contemporary definitions of this and that provided by email queries. Sixty subjects were shown pictures of eleven apples and were asked which specific apple they liked best and which specific apple they liked least. The response pairs of NS’s and NNS’s were compared to see if they were significantly different. Chi-square tests showed that NNS’s used [ðIs] as their first response and [ðæt] as their second response significantly more often than NS’s. The research suggests that definitions and rules traditionally found in books and which are taught in ESL classes are more descriptive of behavior of NNS’s than that of NS’s in a real world situation. Thus, this research suggests the possibility that the use of these rules in ESL teaching may lead to speech that is not native-like.