Adjectives are words that modify nouns. They describe nouns by telling us the color, age, size, or some other characteristic of that noun. Unlike adjectives in some languages, in English they have a single form - they do not change according to gender, number, or location in the sentence.
Many consonant sounds come in pairs. For example, P and B are produced in the same place in the mouth with the tongue in the same position. The only difference is that P is an unvoiced sound while B is a voiced sound.