Purpose: Using second year central and regional teachers’ college students, the purpose of this study was threefold: (a) to examine the students levels of apprehension of words and idioms; (b) to find out the correlation between their ability to apprehend selected ordinary words and idioms; and (c) to determine the influence of their sex, geographical setting, and scholastic achievement on their ability to apprehend. Procedure: Two sets of tests were designed by the author: the first one was ordinary word-oriented while the second was idiom-oriented. Both of them were of similar length and pattern, namely sixty multiple choice items. All of the items yielded relevant data after they had been pretested and systematically validated. One hundred eighty-two boys and one hundred ninety-eight girls took the tests. The results were then interpreted in terms of statistical means, standard deviations, Pearson’s product moment correlations and the z-values. Results: 1. The level of apprehension of ordinary words and idioms of the students was 57.2342 of the mean and 13.3770 of the standard deviation. 2. The students’ ability to apprehend the material on the two tests was correlated; the correlation was .6315 at the .01 level of significance. 3. The correlation of the marks form the researcher’s tests and their marks in subjects in the Thai language curriculum were: Thonburi: .2926, Chankasem: .5149, Pibulsongkram: .3932, Uttaradit: .4012, at the .01 level of significance. 4. The correlation of the marks from the researcher’s tests and the marks of the students’ general scholastic achievement were: Thonburi: .2905, Chankasem: .4962, Pibulsongkram: .4007, Uttaradit: .4035, at the .01 level of significance. 5. The group of girls scored higher than boys on these two tests at the .01 level of significance. 6. The group of students from the central region got higher marks than students from regional teachers’ colleges on the tests at the .01 level of significance.
