I have 2 self study books essential grammar in use(red) and english grammar in use(blue). Blue one is harder and there are explanations about the questions like is it possible to use present continuous while we are not actually doing it etc. But i have also problems with some basics like at,in,on etc. Is it just waste of time repeat the everything in red books or should i start from (As you can see i have also problems with verbs with prepositions because i'm not sure from is the right choice) the blue book ?
Hi TrauM;

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Learning a language is like climbing a ladder - you have to start at the basics. If you repeat some basics later on, that is good reinforcement. You can go over material you have already learned quickly. Reinforcement and extra practice is not a waste of time.

And, yes, you do have problems with articles. That is one of the most elementary parts of English, but also the most difficult to master. Start with the red book, and learn what it teaches. Then go to the blue book, and get the new material and reinforcement of the rules and patterns that were in the red book.

You can also post questions here, and get the opinions of native speakers!

grammar in use(red) Book- I am reading, it is very Good