We need to use the right preposition in English to state our message clearly.

We use the words explain and tell everyday. Make sure you know the grammar when using them.

With explanations and examples.

Grammar differs from language to language and so preposition use varies.

We use this word daily. Do you know which preposition to use? There's only one. This is Part 1: Grammar.
Part 2 explains the pronunciation.

Grammar in the romance languages is different from English grammar. If you want native speakers to understand you, you will want to use word order they'll understand.

Verb tense use indicates your proficiency in a language. Learn more about when the simple present is used, and when you should be using other tenses.

This is Part 2 about the word "focus" and it talks about which preposition is correct to use. See Part 1 to learn how to say focus to be well-understood - not misunderstood!

Our communication in any language is based on a set of rules called grammar. Standard, correct usage is important to be understood and your level appreciated.