The aim of this research was to find out the effectiveness of Climbing
Grammar Mountain Game (CGMG) for teaching simple present tense at the seventh
grade students. This research belonged to quasi experimental research. The subjects
of the research were 60 students in one of junior high school in Banyumas of which
VII E was the experimental class and VII A was the control class. In collecting the
data, this research used test, namely pre test and post test, and the instrument was
tried out to part of the seventh grade students of SMP Negeri 1 Kembaran which
aimed to know the validity, reliability, and item difficulty. The two tests consisted of
15 multiple choice items, 5 gap filling items, and 5 items of making sentences. This
research used t-test as a tool to analyze the data. Based on the t-test computation, the
result of t-test was 4.240, and the value of t-table at the significant level 0.05 for
degree of freedom 58 was 1.671. It could be concluded that t-test result was higher
than t-table (4.240 > 1.671). To sum up, Climbing Grammar Mountain Game was
effective for teaching simple present tense at the seventh grade students of SMP
Negeri 1 Kembaran in academic year 2018/2019.