The question of whether teachers should provide feedback on grammar accuracy in writing assignments for EFL students has been a subject of endless discussions in the field of language learning. Thus, researchers still don’t have any conclusive answer to the question of teacher written direct/indirect feedback. The study presented in the book is experimental, i.e., the samples for the study were randomized. Twenty nine Armenian EFL students and one teacher, also the researcher, participated in this experimental study. This research investigated the data of experimental and comparison groups to establish any significant difference between the results of the groups. The experimental group received teacher written direct feedback, while the comparison group received teacher written indirect feedback. Both groups wrote pre and post compositions in the second and tenth weeks respectively. The research was aimed to find out which type of teacher written feedback is more useful for the improvement of grammar accuracy of learners’ English writing. The study might be interesting to scholars and teachers who have been working over the controversial issue of feedback efficiency in writing.