This guide to English grammar explains clearly what verbs, nouns, adjectives, prepositions, and other grammatical items are and how they are used in the English language.
The explanations are authoritative and detailed enough to provide a deeper understanding of the way that English grammar works, particularly relevant to the work of TESOL/TEFL teachers and students.
The tenses are presented in a grammatically logical order and grouping. This is not necessarily the same as the order that teachers should present them to their students. Some tenses are far easier to learn and far more important/useful than others for general communication.
Students prioritise their efforts and learn the tenses that will give them most benefit at each stage in their learning.
Lots of examples are given from current English usage to make concepts and definitions clearer. The emphasis is on how English language is actually used - not on old-fashioned rules, but on how English language is used by educated speakers in a wide variety of realistic and relevant situations.