Illustrate, by the use of a, b, and p, the difference between the sounds of letters and their names. Letters are the signs of what? What is an idea? A spoken word is the sign of what? A written word is the sign of what? How do they differ? To what four different things did we call attention in Lesson 1?

How are vowel sounds made? How are the two kinds of consonant sounds made? What are vowels? Name them. What are consonants? What is artificial language, or language proper? What do you understand by natural language? What is English grammar?

What three kinds of expressions are spoken of in Lessons 3 and 4? Give examples of each. What is a sentence?