This is a terrible book for learning any language, much less Slovak. Many of the vocabulary words are actually Czech, not Slovak, or haven't been used in Slovakia for years (the word for parking lot, for example). In some cases, the vocabulary is just plain wrong. In the very first lesson, for example, a person says to another on an airplane "did you drop your glasses?" but for glasses uses the work "pohare" (glasses you drink from) rather than okuliare (glasses you wear on your face). OK, the context never makes clear which one the speaker is talking about, but please, would you ever say to your seatmate "Are these your drinking glasses on the floor"? And every gramatical element of Slovak is present in the first dialogues, rather than introducing them gradually, and many of them are never explained. This is a disaster for beginners because Slovak has many complex gramatical structures that might seem obvious to a speaker of a Slavic language but are mysteries to native speakers of English. Frankly, there are no really really good books on learning Slovak, but some are better than acceptable and the book by Naughton is probably the best there is and can be recommended. The Letnanova book, on the other hand, is a disaster.

This book is built around a series of dialogues and vocabulary. It doesn't have much of the other things you need for learning a language such as grammar points and exercises. Though it's more extensive (with the cassettes), you're much better off with Naughton's book. Even so, I use Letnanova's dialogues as refreshers that give me some variation. Letnanova would probably be OK if you were working with a teacher, but you can't learn Slovak by yourself from this book.