Regardless is a word in standard English. Irregardless is not.
Short version of the story: the less takes care of having to put ir in front of regardless.
Don’t say “irregardless.” Just say “regardless.”
(Apparently, irregardless is a word in some dialects, used to shut down a conversation. So unless you grew up with it as part of your culture, and you want to be rudely abrupt, don’t use it!)
We hear this phrase nearly every day, but mostly from advertisers. It’s an emphatic and wrong way of saying “each.” As you can see from the accompanying image, there is a difference between the two words, and it’s good to learn that difference so you can use each word correctly every time. (See what I just did there?)
But the two words, when used in tandem, mean nearly the same thing. So there is no need to say it twice. It’s redundant, and repetitive, and says the exact same thing over and over again. (See what I just did there?)
So say “each” or “every.” Just don’t say them together.
These two get mixed up every day because they sound the same; it’s an everyday problem.
Every day is a two-word phrase that is a noun (day) preceded by an adjective (every). So if you’re talking about the days themselves, and you mean all of them, then use the two words every day.
Example: I will pray for you every day until this crisis is over.
I find this exercise easier to do every day.
Everyday, on the other hand, is a one-word adjective that means daily, or commonplace, or ordinary. We often say something is an everyday occurrence, which means it happens (note the two following words) every day.
Example: Use the everyday silver, not the fancy stuff.
This kind of nuisance is becoming an everyday affair.
Just remember: the one word everyday has to describe something other than a day! If you’re talking about days, and you want to allude to each of them in a specific timeframe, then use every and day as two words.