This app is an interactive eBook that includes grammatical rules related to linguistic expressions such as negation, interrogative, conditional sentences, exclamation, exclusion, apology, and many other expressions, in addition to the punctuation marks and how to use them correctly.
It contains high-quality mp3 files and other tools that will make the self-learning process easy and fast.
It also includes a printable version of the workbook [pdf file], which contains a lot of important exercises (with their answers).