Monthsary or Monthsarry? The Correct Spelling, the Plural, and How to Use It

You are typing the message. You have the photo picked, you know roughly what you want to say, and then you stop dead on the third word because you genuinely cannot remember whether it has one r or two. Monthsary. Monthsarry. Monthsery. Monthersary. They all look slightly wrong once you stare at them long enough, which is a thing words do.

So here is the short answer, and then the longer one for anyone who wants to stop second-guessing it for good.

It is monthsary. One r. No e in the middle. Month plus sary, the way anniversary ends.

The double-r version is the most common misspelling by a wide margin, and there is a decent reason for it. English is full of words where a short vowel doubles the consonant that follows - starry, sorry, carry, marry. Your instinct is doing something sensible; it is just applying the wrong rule.

Monthsary is not built from an English root. It is a blend, formed by taking anniversary and swapping the year part for the month part. Because it inherits the -sary ending directly from anniversary, it inherits anniversary's spelling too. Anniversary has one r. So does monthsary.

If you ever get stuck again, that is the whole trick: write anniversary in your head, then replace anni- with month-. You will never double the r again.

For completeness, since these all show up constantly:

Monthiversary is a real, widely used word - it is just a different one. It is built the other way round, keeping the -iversary ending from anniversary and swapping only the first part. Both words mean the same thing: a monthly milestone in a relationship.

The difference is mostly geographic. Monthsary is overwhelmingly the word in the Philippines and across much of South and Southeast Asia, including India. Monthiversary is more common in the US. Neither is more correct than the other, and neither has settled into mainstream dictionaries yet, which is exactly why the spelling feels unstable when you are typing it.

If you are wondering which word to use rather than how to spell it, we went through that properly in the piece on choosing between monthsary, monthiversary and mensiversary. Short version: use whichever one your partner uses.

This one trips people up in captions more than in messages. The rule is the standard English one for nouns ending in a consonant followed by y: drop the y, add -ies.

So it is monthsaries. The same way anniversary becomes anniversaries and not anniversarys.

The possessive is monthsary's, with the apostrophe before the s - as in your monthsary's date. And no, there is no apostrophe in the plain plural, however tempting it looks at one in the morning.

Lowercase, in almost every case. Monthsary is a common noun, like birthday or weekend, not a proper noun like Diwali or Christmas. So you would write our third monthsary, not our third Monthsary.

The exceptions are the ordinary ones. Capitalise it at the start of a sentence, and capitalise it if you are using it as a title - a card that says Happy Monthsary, or a photo album called Monthsary No. 6. Inside a normal sentence, keep it small.

Happy monthsary and Happy Monthsary are both fine as a greeting, incidentally. Greetings get treated a bit like titles, so nobody will blink at either.

Spelling it right is the easy half. The part that actually makes a message land is where the word sits.

The most natural pattern is the same one you would use for an anniversary: an ordinal number, then the word. Our fourth monthsary. Our eleventh monthsary. It reads cleanly and it tells the reader exactly which one you mean.

Digits work fine in casual writing - our 4th monthsary is perfectly normal in a caption or a text. Spelling the number out reads slightly warmer and slightly more deliberate, which is usually what you want if the message is the gift rather than the label on one.

A few forms that work well:

It is worth saying plainly: nobody has ever been hurt by a doubled r. If you send monthsarry to someone who loves you, they will read the message, not the spelling, and the day will be exactly as good as it was going to be.

The reason to get it right is smaller and more practical. You are probably writing this on a phone, at speed, wanting it to feel effortless - and nothing undercuts effortless like retyping a word four times and settling on the version that looks least wrong. Knowing the answer means you stop thinking about the word and start thinking about the sentence.

Which is the point. The word is just a label. What goes after it is the bit they will remember.

One r, an a not an e, one word, lowercase inside a sentence, and monthsaries in the plural. Borrow the spelling from anniversary and you will get it right every time.

And if you are not certain which day your next one actually falls on - which happens far more often than the spelling question does, especially if you started dating near the end of a month - a days together counter will settle it in a second, and tell you which round numbers are coming up while it is at it.