These compound words have hyphens between them.
- check-in
- check-out
- runner-up
- passer-by
- self-esteem
- self-service
- self-employed
- full-time
- part-time
- mother-in-law / father-in-law (rare in IELTS but useful to know)
- brother-in-law / sister-in-law
- son-in-law / daughter-in-law (plural: sons-in-law, not son-in-laws)
- passer-by
- editor-in-chief
- commander-in-chief
- well-known
- well-developed
- up-to-date
- state-of-the-art
- high-quality
- low-cost
- first-class
- long-term
- short-term
- user-friendly
- energy-efficient
- cost-effective
- stress-free
- hands-on
- time-consuming
- English-speaking (e.g., “an English-speaking country”)
- part-time / full-time (when used as adjectives: “a part-time job”)
- middle-aged
These are non-hyphenated words
- airport
- armchair
- backyard
- babysitter
- backpack
- basketball
- bathroom
- beachball
- bedroom
- blackboard
- bluebird
- bodyguard
- bookcase
- bookmark
- bookshelf
- brainstorm
- campsite
- carpool
- childcare
- classroom
- cookbook
- courtyard
- crosswalk
- cupcake
- daycare
- dishwasher
- doorbell
- doorknob
- downstairs
- driveway
- earthquake
- eyelid
- fingernail
- fingerprint
- fireman
- flashlight
- footprint
- football
- girlfriend
- greenhouse
- haircut
- handshake
- handmade
- homework
- houseplant
- housework
- iceberg
- keyboard
- laptop
- lipstick
- mailbox
- milkshake
- moonlight
- notebook
- oatmeal
- pancake
- playground
- popcorn
- raincoat
- rainbow
- shoelace
- skateboard
- snowball
- snowflake
- snowman
- softball
- spaceship
- spotlight
- suitcase
- sunflower
- sunlight
- superman
- swimming pool
- tablecloth
- tablespoon
- teardrop
- toothbrush
- toothpaste
- upstairs
- volleyball
- wallpaper
- watermelon
- weekend
- wheelchair
- windbreaker
- windmill
- workshop