Then there’s the Indian Myna bird, and the Australian Noisy Miner bird.
My husband.
My favorite husbandism was “we have to put our butts to the metal.”
He’s the only person I will actually correct.
Heh - “husbandism”. Great term!
I sometimes enjoy creating those mixed malapropisms just to see if I can get a response out of somebody. But I know if I’m doing that; and if not I’ll be using an existing idiom correctly.
Is that your husband, or is he doing this unconsciously?
tax return: the paper or electronic form(s) that a taxpayer or his or her preparer fills out and sends to the tax authorities that indicates, among other things, how much tax is owed
tax refund: the money the tax authorities remit back to the taxpayer if the taxpayer has overpaid his or her taxes (e.g., through paying more in withheld taxes throughout the year than what the tax liability is calculated to be on the tax return)
It’s totally unconscious for him. He is a highly intelligent man and I think his thoughts come faster than he can get them out of his mouth, so these mixups occur a lot. It’s also very common that he gets single words confused with similar words - he’d probably benefit from reading this thread.
Someone mentioned prevaricating - until recently I was under the impression this meant something like vacillating, until a writer friend helpfully pointed out, “I don’t think it means what you think it means.”
warship: any naval ship used for combat, including cruisers, destroyers, and submarines
battleship: a particular type of surface warship, common from the late 19th century to the mid-20th century and known for its heavy armor and large guns.
The United States Navy currently has hundreds of active warships, but zero active battleships. The last one, U.S.S. Missouri, was decommissioned in 1992. Recent proposals for a new so-called “Trump-class battleship” are controversial because they (1) probably will never be built and enter service, (2) would serve no very useful purpose if they were built, and (3) would not meet the usual definition of a battleship.
trammel: (1, n) something that impedes freedom or (2, v) to impede, hamper, or hinder someone’s freedom. Hence, untrammeled means “unrestrained.”
trample: (v) to crush something by stepping on it heavily, literally or figuratively. Hence untrampled means “not crushed underfoot.”
When speaking about threats to civil rights and freedoms, both words can be used, but I think there is a difference. To trample another’s rights is to utterly destroy them, while to trammel another’s rights is to restrict them. Trampled is a more common word than trammeled but untrammeled is more common than untrampled.
apprise : to give notice to; inform
appraise: to estimate the monetary value of; determine the worth of; assess.
doughy: pale and pasty like dough
doughty: brave, dauntless
Perhaps the generals of World War One boasted that their soldiers were “doughty” when in fact they were more “doughy”. 
Well, they WERE called doughboys, weren’t they?
Exactly. 
isn’t it interesting that in English adding 1 letter anywhere inside/after a word can change the whole meaning of it?
Or removing. I once saw a typo which went something like:
After 6 hours on the road the coach stopped, the passengers were able to stretch their legs and the driver was hanged.
I have absolutely no doubt that on multiple occasions the passengers of a coach wished that the driver could have been hanged.
“They said you was hung!”
Stocks and Pillory. The words aren’t similar, but a lot of people say one when they mean the other.
A pillory traps someone’s neck and hands.
The stocks traps someone’s legs