Learn some opposite adjectives:

dry-wet, small-big, long-short, low-high, good-bad, hard-easy, true-false, light-dark, young-old, clean-dirty, heavy-light, short-tall, rich-poor, strong-weak, sour-sweet, thin-fat, old-new, soft-hard, thin-thick, up-down, front-back, expensive-cheap, fast-slow, cold-hot