"STATIONARY" and "STATIONERY"

"Stationary" means not moving or not changing. "Stationery" refers to writing materials, such as paper, pens, and envelopes. Ex.: The car remained stationary at the traffic light. I need to buy some stationery for the office.

"ALTOGETHER" and "ALL TOGETHER"

"Altogether" means completely or in total. "All together" means everyone or everything in a group. Ex.: The project was altogether successful. We sang the song all together.