IN A SENTENCE:

It’s that STATIONARY yellow cart in the office that holds all the company’s STATIONERY and letterheads.

DISCLAIMER: I am not an English Native Speaker nor an expert in English language. What I write here are all from experience and research. If you feel I am out of line or say the wrong things, please alert me in the comments. To this effect, I am not immuned to these confusing words myself and this series is as much as an education for me as to those who read these blog posts.

PHOTO SOURCE: LINKEDIN.COM

STATIONARY VS. STATIONERY

STATIONARY

...is an ADJECTIVE meaning not moving or not intended to be moved.

PHOTO SOURCE: BRONZEBIKERALLY.COM

Example #1: You can do cardio exercise in a gym with a STATIONARY bike.
Example #2: The train remained STATIONARY for 5 minutes at a station due to heavy rainfall.

STATIONERY

... is a NOUN, in fact, a MASS NOUN, which refers writing materials mostly manufactured for commercial purposes; this also includes office supplies that relates to writing.

PHOTO SOURCE: PRADEEPSTATIONERS.NET

Example #1: Our office orders STATIONERY from Office Depot because they offer free delivery.
Example #2: When I came back from coffee break, the STATIONERY on my desk was a mess!

HOW THEY ARE PRONOUNCED

FURTHER STUDY:
http://writingexplained.org/stationary-vs-stationery-difference
http://blog.dictionary.com/stationary-vs-stationery/
http://www.grammar-monster.com/easily_confused/stationary_stationery.htm
http://blog.oxforddictionaries.com/2015/04/stationary-or-stationery/
http://www.quickanddirtytips.com/education/grammar/stationery-versus-stationary

I hope we learned something new today. I surely did! See you in the next confusing words! If you like this series, please follow @cjclaro and upvote and resteem ;-)