Tomorrow or On Tomorrow? Turning That ‘On’ Off


Should you refer to something happening tomorrow or on tomorrow? A largely-Southern expression adds the preposition before words like today, tomorrow and yesterday, and we need to turn that option off.

Like many other people, the first time I heard someone say they were going to do something “on tomorrow,” I thought it was a simple mistake. Since then, I’ve heard “on today” and “on yesterday” as well.

It’s a bizarre little construction that makes little sense, until you consider that there’s absolutely nothing wrong with saying, “I’ll meet with him on Tuesday.” When you consider that a day with an actual name needs the on preposition to make sense, then it seems like someone’s just trying to be consistent by adding the on across the board.

Okay, so even if there might be some degree of logic in play — or at least an attempt at some sort of logic — that still doesn’t make “on tomorrow” sound any more correct to those of us who don’t use such an expression.

Here’s where you have to let out your inner grammar nerd long enough to figure out why you don’t need on in front of words like today, tonight, tomorrow or yesterday.

Words like today used to be written as “to-day.” The preposition to eventually became a full-fledged part of the word when people started writing it without the hyphen. But even as one word, the preposition is implied, so on is redundant. Yesterday is only slightly different, but its definition is “on the day before today,” so adding another on is obviously redundant there, too.

So unless you’re referring to a specific day with its own name — such as Sunday, Monday, etc.; or an event on a calendar — like Thanksgiving Day, Christmas Day, etc.; you don’t need on.

Have you ever heard expressions like “on tomorrow” or “on today”? Do they set off your internal grammar alarm?


  1. “On __________” leaves the same, deep abrasion on my grammatical sensibiliy as does, “gone missing”, in place of, “disappeared.”

  2. Incorrect grammar is incorrect grammar. No matter where the phrase started, it is incorrect grammar. How are you going to do something ON tomorrow? Stand on it? Stand on a piece of paper with it written on it? You will do something tomorrow, not ON tomorrow.

  3. What you refer to as “inner grammar nerd” should probably be relabled “inner class-based linguistic judgement system”.

    Language is not standardized, it’s simply appears that way because most of use stay in our boxes and never actually wander into those places that challenge our notion of what is “normal”. In some places, we a language similar enough to ours in order to make the assumption that it IS ours, but one actually operates on a divergent form of grammar that is functional in one case and “broken” in another. 
    Of course, something is only assumed to be broken when looked at from a position of privilege. Consider the now-amusing notion the British have that Americans speak a mongrel version of their language, then look at the types of language that you most consider to be “broken” or “strange”.

    1. Dear R, I agree that to judge another’s “home language” (the vocabulary learned at home) as incorrect is elitist by today’s standards, but on the other hand, you have to look at the context of the interaction. When I speak to a student conversationally, it would be rude to correct his/her home language. But in writing assignments or group discussions, there’s nothing wrong with addressing the very real fact that most white collar jobs expect its employees to use “business English.” I realize we are talking about adults, not children, but I am also someone who cringes when I hear “on tomorrow,” and I think early training would help to understand that there is nothing wrong with using our home language but we also need to know the language of the business world. And by the way, I hear “on tomorrow” nearly every day when my principal says it over the intercom at the end of the day, and I have learned to ignore it…mostly.

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Patrick is a Christian with more than 30 years experience in professional writing, producing and marketing. His professional background also includes social media, reporting for broadcast television and the web, directing, videography and photography. He enjoys getting to know people over coffee and spending time with his dog.