بررسی آغازگر نشاندار و بی‌نشان در کتب زبان انگلیسی مقطع متوسطه در ایران، براساس رویکرد نقش‌گرای نظام‌مند هلیدی

Historically, scholars of language teaching have got the advantage of linguistic theories and used their findings to get a better teaching outcome. However as many experts believe, English teaching in Iran has not been successful mostly because of the lack in scientific basis. Many studies have been conducted based on Halliday's systemic functional grammar since it emerged to apply its benefit in language teaching. This research has tried to have a textual analysis on Iranian high school English text books based on the mentioned theory to specify the kind and the frequency of themes in the text reading of these four books. After the analysis of 1303 clauses, the results showed that there is not a definite pattern in organizing the texts based on the kind or the frequency of the clauses and in opposition to our expectations, the frequency of marked themes, which can result in a higher difficulty level of a text, has not increased from lower levels to higher ones. Marked themes are even more frequent in grade one.