Lengua teaches grammar by teaching the user how the rules are used in context. For example, in Spanish the verb is conjugated differently depending on formality. For the sentence ‘What is your name?’ Lengua teaches you both the informal (¿Còmo te llamas?) version and the polite (¿Còmo se llama usted?) version. Easy! After learning a few examples like this, you develop an intuitive “feel” for the grammar.