Box of L Clusters: blue, blocks, blanket, black, blink, blizzard, slide, slope, slither, slip, slug, slow, sleep, slimy, clean, closet, clap, close, claw, clock, clicker, climb, cloud, fly, flap, flame, flower, floss, float, flute, glue, glass, glitter, glove, globe, gloomy, planet, plane, play, please, plant, plow
Box of S Clusters: skunk, skating, scoop, scarf, skull, scare, squeal, scream, scuba, mask, lobster, skip, skirt, slide, slippery, slug, slimy, sled, sledding, smell, stinky, smoke, smoky, smash, small, smile, smirk, snickering, snow, snowflake, snail, slime, snack, snap peas, snuggle, snooze, sleep, snoring, snake, sneeze, stop, stop sign, stopped, sticking, sticker, story, stamp, sticky, postage, post office, stone, step, stairs, staircase, monster, dentist, swing, swinging, swaying, swan, swimming, swamp, sweep, sweater, swimming, swamp, swat, swoop, sponge, space, spaceship, stars, spoon, speech, speaking, spooky, spider
Box of R Clusters: brain, brown, bread, broom, breakfast, bridge, crane, cranking, cry, cranky, crayon, creepy, crawler, creek, crazy, green, grass, grasshopper, ground, grapes, growing, groceries, grill, grate, grumpy, grouchy, grizzly, grumble, growl, drive, drawing, dress, dragon, drumming, drum, drink, dribble, dream, dreamy, drowsy, drop, drill, pretty, princess, bracelet, prince, pretzel, practice, print, proofread, proud, present, prize, price, frown, frustrated, fresh, fruit, friend, frozen, freezing, Friday, frog, freckles, friendly, friends, frisbee, tropical, tree, trunk, truck, trouble, treasure, train, tracks, triangle, trampoline, tractor