Correct spelling, explanation: supposed first appeared in the English language in the times of Middle English, but the origin of the word can be found in the Latin form suppositus, which could be translated as set under. The Latin form of supposed, on the other hand, comes from the words sub and ponere. The former one meant from below while the latter one could be translated as to place.

Definition of supposed:
1. adjective – to have to do something,
You are supposed to start work at 8.00 a.m. but it’s almost 9.00 and you aren’t even in the office.
2. adjective – intended,
This low-energy lightbulb was supposed to last for at least a year, but it’s already broken.
3. adjective – used when you want to show that you don’t believe that something or somebody is what other people consider them to be,
According to our teachers, he’s a supposed genius, but I know he’s simply a swot.

Collocations with supposed:
A few common collocations with supposed are: be commonly supposed, be supposed to do something, and be generally supposed to.
This combination of numbers is commonly supposed to appear in this particular computer program.
John was supposed to look after his younger sister, but he totally forgot about it and spent the whole afternoon at his girlfriend’s place.
He’s generally supposed to clean the area every day, but today he called and asked for a day off.

Incorrect spelling, explanation: the base form of supposed is actually suppose and as the verb ends with an -e letter, when the past participle is formed, we only have to add a -d letter. However, maybe due to the pronunciation of supposed, a number of English speakers spell it as suppost, which is incorrect.

Incorrect spelling

Incorrect spelling

Incorrect spelling