English is full of very confusing rules, sentence structures and spellings. I am grateful that it is my native tongue, because I would hate to have to attempt to learn it as a second language. Even as a native speaker, I make mistakes all the time and would not be surprised if I made a mistake in this very post.
That said, if you are advertising lessons on how to speak English Clearly, Correctly & Fluently, you should probably try to avoid including the phrase “very less time” on the same poster.
But that’s the great thing about being the ‘expert’ teacher. Even if you get it wrong the paying student will never know the difference!
Viva the free market!!