- All right vs. alright
- All together vs. altogether
- Already vs. all ready
- Awhile vs. a while
- Back up vs. backup
- Backyard, back yard, and back-yard
- Bailout, bail out, and bail-out
- Beeline
- Blowout and blow out
- Blowup, blow-up, and blow up
- Build up vs. buildup
- Burnout vs. burn out
- Bus stop or busstop?
- Check up vs. checkup
- Cleanup vs. clean up
- Everyday vs. every day
- Follow up, follow-up, followup
- Freshwater
- Healthcare
- Hunter-gatherer
- Knee-jerk, kneejerk
- Leftover vs. left over
- No one vs. noone
- Offhand
- Onboard vs. on board
- One-time vs. onetime
- Oneself vs. one's self
- Overnight vs. over night
- Payback vs. pay back
- Pullout, pull-out, and pull out
- Right-of-way
- Rollout vs. roll out
- Rollover vs. roll over
- Runaway vs. run away
- Saltwater vs. salt water
- Someday vs. some day
- Sometime vs. some time
- Standby vs. stand by
- Timeout vs. time out
- Underwater vs. under water
- Underway vs. under way
- Upfront vs. up front
- Voicemail
- Website, web page
- Workout vs. work out
- Write-off vs. write off