Learning a language is like learning to ride a bike -- it's something that you have to do in order to learn. There is no book that can teach you to ride a bike; there is no book that can teach you to speak a language, without your using the language.
Verbs are like the branches of a tree. You can make virtually infinite sentences using just a single verb. How many sentences could you make beginning with the verbs 'I am ...', 'I have ...', and 'I like ...'? The vocabulary you use to the complete the sentence are like the leaves upon the branch. Trying to learn a language by learning vocabulary is like trying to make a tree grow by planting leaves. Vocabulary without a verb is like leaves without a branch -- they will fly away in the wind.
Once you are up on the bike, riding, able to communicate on a few topics using a few verbs and just the vocabulary you need, you will begin understanding more of what you hear when you listen to others speak the language. At that point, your learning the language will become spontaneous and automatic. Some of the questions you may have about the language might be answered in the form of song lyrics or a text from a friend. You're like a snowball rolling downhill -- picking things up as you go, becoming bigger and heavier, and thereby rolling even faster and learning more. The goal at the beginning is to reach the point where you become heavy enough that you can roll by yourself.
To summarize, leverage verbs as the nuclei of conversation, and have conversation until your learning becomes automatic.