Correct spelling, explanation: the word presumed originates from the Middle English word presumen, which comes from the Old French presumer, ultimately derived from the Latin verb praesumere, meaning to take beforehand or to anticipate. On the other hand, presumptive comes from the noun presumption with the suffix -ive added, forming an adjective. Presumption is derived from the Latin praesumptionem, which is the noun form of praesumere, the same root as presumed. The two words have similar origins but have evolved into distinct parts of speech with slightly different meanings and uses.

Definition of presumed:
Verb (past simple and past participle of presume), to believe something to be true because it is very likely, although you are not certain
In the absence of any concrete evidence, the missing hiker was presumed to have gotten lost in the wilderness.
The archaeologists presumed the age of the artifacts based on their context within the excavation site.

Collocations with presumed:
Some of the most commonly used collocations include:
1. Presumed dead: referring to individuals who are believed to have died in the absence of evidence to the contrary.
After weeks of searching, the missing climbers were presumed dead.
2. Presumed innocent: describing the legal principle that individuals are considered innocent until proven guilty in a court of law.
The defendant is presumed innocent until proven guilty beyond a reasonable doubt.
3. Presumed cause: referring to the assumed or likely reason for a particular event or outcome.
The presumed cause of the plane crash is currently under investigation.
4. Presumed knowledge: referring to information or understanding that is assumed to be possessed or understood by others.
The lecturer skipped over the presumed knowledge and delved straight into the advanced concepts.

Correct spelling, explanation: presumptive and presumed are used in different contexts, so the choice between them depends on what you’re trying to convey. Use presumptive when you want to describe something that is based on presumption, assumption, or likelihood, often with a provisional or preliminary connotation. It’s commonly used in situations where there’s an expectation or assumption of something happening or being true, but it hasn’t been confirmed definitively. Use presumed when you want to indicate that something is believed to be true or accepted as true without conclusive evidence or proof. It implies a strong assumption or belief in the absence of definitive confirmation.