How to express the notion of doing something deliberately or on purpose, I mean. Personally, I dislike “purposely”. It just sounds uneducated. “-ly” normally goes on the end of adjectives, not nouns, to form adverbs.
“Purposefully”, meanwhile, to me means “determinedly”, “with some larger goal in mind”, rather than merely “on purpose”.
So I prefer “purposedly”, meaning “with a particular purpose”. It’s like if you’re doing something in a hurry - you don’t do it “hurrily” or “hurrifully”, you do it hurriedly.
Purposefully and purposedly have two quite different meanings.
Look them up in dictionary.com It’s too late in the evening here for me to do that task for you.
Purposely is the only one I’ve heard of used in that way. Purposedly sounds odd, and I’ve never heard it used, although I guess it’s technically correct. Is that pronounced pur-poséd-ly? Purposefully is, as you suggest, a completely different word.
Although adverbs are often formed in that way, there is no rule about how they’re formed. Most of the comparison words can be adverbs and don’t end in -ly.
I already described the different meanings in the OP. But it seems to me that people do often incorrectly use “purposefully” to mean “on purpose”, maybe because like me they find “purposely” unsatisfactory.
I didn’t say that adverbs must end in “-ly”. I said that when they do, they are almost always derived from an adjective, not a noun. I’m struggling to think of any exceptions.
Purposely is the only correct choice for what I think you mean – to do a thing with a purpose.
Purposefully means to do a thing in a purposeful manner – one may move purposefully, but one need not do so even if one has a purpose.
Purposedly, on the rare occasion that anyone uses it, means to do a thing in a purposed manner, where “purposed” is the past tense of the verb “to purpose,” meaning more or less the same thing as “to intend.” It’s similar, I think, to “determinedly.”
And insisting on nonexistent rules to justify mucking with English grammar or usage seldom ends well.
“He purposely included a false statement to entrap his enemies.”
“He purposefully placed the rock in front of his neighbour’s path.”
“He purposedly did time in Nebraska, in '84.”
I usually just avoid this mess and use intentionally.
This thread has me thinking of porpoises.