口 KOU3, mouth
口袋 KOU3 DAI4, pocket
可口可樂 Ke3 kou3 ke3 le4 Coca-cola (literally, Tasty delightful)
Etymology note: This character was originally a pictogram of an open mouth. Like other characters, it was stylized by being "squared off."
Allow me to recommend chinesepod.com for aural language practice. They offer lessons for levels "newbie" to "advanced." Downloading the podcasts is free.