"Tired" vs "Sleepy"

Don't confuse the two, they are different...

In my experience, ‘sleepy’ is just sleepy, you simply want to go to sleep. You can be sleepy any time, even during the time you shouldn’t be tired. Ever tried attending some lectures or seminars that eventually you fell asleep in the course? You may have the best intention to stay awake but the environment, lighting, speaker’s tone and most importantly the ventilation will cast spell on you.

‘Tired’ is the other way round. You really need some rest, and better be deep rest. Your body may give you explicit signals that you are tired, but not necessarily you can go to sleep. And that’s what I am experiencing right now! I feel like I can be awake long enough to finish another long chapter of textbook, but physically my body tells me that I may not have that much energy.

So… By no mean you should feel sleepy during work, but it may be understandable if you feel tired — Even though both terms will not be acceptable for your boss.