Mondays or Monday’s: Which Is Correct? Complete Grammar Guide

Mondays or Monday’s can both be correct, but they do not mean the same thing. Mondays is the plural form of Monday and usually refers to multiple Mondays or a recurring Monday routine. Monday’s is normally a singular possessive form or a contraction of Monday is or Monday has. There is also a fourth form, Mondays’, which is the plural possessive.

The right choice depends on what you are trying to say.

Quick Answer: Mondays or Monday’s?

The most important rule is simple:

Use “Mondays” when you mean more than one Monday. Use “Monday’s” when the apostrophe has a grammatical job, such as showing possession or forming a contraction.

Apostrophes are not normally used simply to make ordinary nouns plural. They can show possession or indicate omitted letters in contractions.

Monday, Mondays, Monday’s, and Mondays’: The Four Forms

Understanding all four forms makes the difference much easier to remember.

1. Monday

Monday is the singular form. Use it when you mean one particular Monday.

Examples:

• I have a dentist appointment Monday.
• We are meeting next Monday.
• The office is closed this Monday.
• I finished the report last Monday.

Words such as this, next, and last commonly identify a particular Monday, so the singular form is appropriate.

Compare:

• I will see you Monday. — one specific Monday
• I see my doctor on Mondays. — Mondays in general or as a recurring routine

2. Mondays

Mondays is the ordinary plural form of Monday.

Use it when you are talking about multiple Mondays or a recurring event that happens on Mondays.

Examples:

• I work from home on Mondays.
• Our team has meetings on Mondays.
• Mondays are usually busy at the office.
• I take my children to school every Monday.
• Most Mondays feel the same during the semester.

Notice that the plural does not require an apostrophe.

Mondays = more than one Monday.

Monday’s = something different.

This follows the general principle that an apostrophe is not added merely to make an ordinary noun plural.

3. Monday’s

Monday’s has more than one possible grammatical function. This is one reason the form can be confusing.

It can be:

1. A singular possessive
2. A contraction of Monday is
3. A contraction of Monday has

Monday’s as a singular possessive

Use Monday’s when something is associated with, belongs to, or is connected with one particular Monday.

Examples:

• Monday’s meeting was canceled.
• Monday’s schedule is already full.
• I checked Monday’s weather forecast.
• Monday’s deadline is earlier than I expected.
• We discussed Monday’s agenda.

Here, Monday’s modifies a noun.

For example:

Monday’s meeting

means the meeting associated with Monday.

The same possessive pattern applies to singular nouns generally: a singular noun can take ’s to show possession or a close relationship.

Monday’s as a contraction of “Monday is”

Sometimes Monday’s does not show possession at all.

It can be a contraction of:

Monday is

Examples:

• Monday’s going to be busy. = Monday is going to be busy.
• Monday’s the first day of my new job. = Monday is the first day of my new job.
• Monday’s better for me. = Monday is better for me.

Apostrophes are used in contractions to represent omitted letters, and ’s can represent is. ([Cambridge Dictionary][1])

Monday’s as a contraction of “Monday has”

Less commonly, Monday’s can also represent Monday has when has is functioning as an auxiliary verb.

For example:

• Monday’s been unusually quiet. = Monday has been unusually quiet.

The context tells you whether Monday’s means Monday is or Monday has.

This is another reason it is inaccurate to say that Monday’s always means possession. The apostrophe can also represent omitted letters in a contraction. ([Cambridge Dictionary][1])

4. Mondays’

Mondays’ is the plural possessive form.

It is used when you are referring to something associated with multiple Mondays.

For example:

• The Mondays’ schedules were different.
• The manager compared the Mondays’ attendance records.
• The two Mondays’ meetings were held at different times.

The structure is:

Mondays → plural Mondays’ → plural possessive

Because Mondays already ends in s as a regular plural, the possessive apostrophe is placed after the final s. This follows the standard pattern for regular plural possessives.

Mondays vs. Monday’s: What Is the Difference?

The easiest way to distinguish the two is to ask what grammatical job the word is doing.

Use “Mondays” for plural meaning

Use Mondays when you mean multiple Mondays.

• I dislike Mondays.
• We have meetings on Mondays.
• She works late on Mondays.
• Most Mondays are hectic.

Here, there is no possession and no contraction.

Use “Monday’s” for possession or contraction

Use Monday’s when you mean:

• something associated with one Monday, or
• Monday is, or
• Monday has

Examples:

• Monday’s meeting starts at noon.
• Monday’s going to be difficult.
• Monday’s been hectic already.

So:

I work on Mondays. More than one Monday.

But:

Monday’s meeting was canceled. The meeting associated with one Monday.

And:

Monday’s going to be difficult. Monday is going to be difficult.

Sometimes the Correct Answer Is Simply “Monday”

One common mistake is assuming the choice must always be Mondays or Monday’s.

Sometimes neither is appropriate.

If you mean one particular Monday, use the singular Monday.

Examples

• I will call you Monday.
• We met last Monday.
• The interview is next Monday.
• I am free this Monday.
• What are you doing on Monday?

Adding an apostrophe would change the grammatical function:

• Monday’s meeting = a meeting associated with Monday
• Monday = the day itself

This distinction is especially useful when choosing between Monday, Mondays, and Monday’s.

Every Monday vs. Every Mondays

The correct standard expression is:

every Monday

Not:

every Mondays

The reason is grammatical rather than stylistic. Every is used with a singular countable noun when it refers to individual members of a group or repeated occasions.

Examples:

• I exercise every Monday.
• We have a staff meeting every Monday.
• She visits her parents every Monday.
• The newsletter is published every Monday.

You can still talk about repeated Mondays without using the plural noun directly after every:

I work from home every Monday.

This means the activity happens repeatedly, one Monday at a time.

Compare:

• every Monday — standard
• every Mondays — not standard in edited English
• on Mondays — standard
• most Mondays — standard
• some Mondays — standard

The difference is not that one expression describes repetition and the other does not. Every Monday already expresses repetition.

READ MORE >>> Openned or Opened: Which Spelling Is Correct?

On Monday vs. On Mondays

Both on Monday and on Mondays can be correct.

The choice depends on whether you mean one particular Monday or a recurring pattern.

On Monday

Use on Monday for one particular Monday.

• I have an appointment on Monday.
• We will discuss the project on Monday.
• She arrives on Monday.
• The store reopens on Monday.

On Mondays

Use on Mondays when something happens repeatedly.

• I work from home on Mondays.
• The gym is crowded on Mondays.
• We have team meetings on Mondays.
• He plays tennis on Mondays.

A useful comparison is:

I am meeting Sarah on Monday. One particular Monday.

I meet Sarah on Mondays. A recurring arrangement.

Context can sometimes make the distinction more nuanced, but this is a reliable starting point.

Monday Morning vs. Monday Mornings

Another common source of confusion is whether morning should be singular or plural.

Monday morning

Use Monday morning when referring to one particular Monday morning.

• I will send the report Monday morning.
• We met on Monday morning.
• The package arrived Monday morning.

Monday mornings

Use Monday mornings when referring to Monday mornings generally or repeatedly.

• I usually exercise on Monday mornings.
• The office is quiet on Monday mornings.
• We have training sessions on Monday mornings.

Notice that the plural belongs to morning, not Monday.

Compare:

Monday morning = one particular Monday morning

Monday mornings = Monday mornings in general

This pattern can help you understand similar expressions involving days and parts of the day.

Is “Monday’s” Always Possessive?

No.

This is one of the most important details to remember.

Monday’s can be possessive:

Monday’s meeting was canceled.

But it can also be a contraction:

Monday’s going to be busy.

In the first sentence, Monday’s means something like “associated with Monday.”

In the second, Monday’s means Monday is.

A quick test is to expand the contraction.

If replacing ’s with is produces a sensible sentence, the word may be a contraction.

Example

Monday’s going to be busy.

Expand it:

Monday is going to be busy.

That works, so Monday’s is a contraction.

Now try:

Monday’s meeting starts at nine.

Expand it:

Monday is meeting starts at nine.

That does not work.

Therefore, Monday’s is functioning as a possessive form.

This simple test can resolve many cases.

Is “Mondays’” Correct?

Yes, Mondays’ can be grammatically correct, but it is much less common than Mondays or Monday’s because plural possessive constructions involving days are relatively specific.

Use Mondays’ when you genuinely need to show that something belongs to or is associated with multiple Mondays.

For example:

The two Mondays’ schedules were completely different.

Here, the schedules belong to or are associated with two separate Mondays.

However, sometimes rewriting the sentence is clearer.

Instead of:

The Mondays’ schedules were difficult to compare.

You might write:

The schedules for the two Mondays were difficult to compare.

The second version makes the relationship explicit and may be easier for readers to process.

So Mondays’ is not wrong simply because it looks unusual. The important question is whether the sentence actually requires a plural possessive.

Common Mistakes With Monday Forms

The central mistake behind many of these examples is treating an apostrophe as a general signal for “more than one.”

It is not.

Apostrophes have specific grammatical functions, including showing possession and representing omitted letters in contractions.

A 5-Second Test for Choosing the Right Form

When you are unsure whether to write Monday, Mondays, Monday’s, or Mondays’, use this sequence.

Step 1: Do you mean one specific Monday?

Use:

Monday

Example:

I will see you Monday.

Step 2: Do you mean multiple Mondays?

Use:

Mondays

Example:

I work on Mondays.

Step 3: Is something associated with one Monday?

Use:

Monday’s

Example:

Monday’s meeting is important.

Step 4: Does “Monday’s” mean “Monday is” or “Monday has”?

Keep:

Monday’s

Example:

Monday’s going to be busy.

Step 5: Is something associated with multiple Mondays?

Use:

Mondays’

Example:

The two Mondays’ schedules were different.

This framework is more useful than memorizing a single rule because the four forms perform different grammatical jobs.

Why Do “Mondays” and “Monday’s” Cause So Much Confusion?

Part of the confusion comes from pronunciation.

Mondays and Monday’s can sound the same in ordinary speech. The difference becomes visible in writing.

That means you cannot always decide which spelling is correct by how the word sounds.

Instead, look at the sentence.

Compare:

I hate Mondays.

Here, Mondays is a plural noun.

Now:

Monday’s meeting starts at ten.

Here, Monday’s is possessive.

And:

Monday’s going to be difficult.

Here, Monday’s is a contraction of Monday is.

The surrounding words reveal the grammatical function.

Monday’s Meeting vs. Mondays Meeting

The correct form depends on what you mean.

One Monday’s meeting

Use:

Monday’s meeting

Example:

Monday’s meeting has been moved to 2 p.m.

The apostrophe marks the relationship between Monday and meeting.

Meetings held on multiple Mondays

If you mean meetings that happen on multiple Mondays, use a construction that clearly expresses the intended meaning.

For example:

The Monday meetings are usually short.

or:

The meetings on Mondays are usually short.

Do not automatically write:

Mondays meeting

That construction is missing the grammatical relationship readers expect.

If you specifically mean that several individual Mondays each have their own meeting, a plural possessive can sometimes be appropriate:

The Mondays’ meetings were scheduled at different times.

However, meetings on Mondays is often clearer when the main idea is simply a recurring event.

Monday vs. Mondays in Everyday Expressions

Several common expressions make the singular/plural distinction easier to see.

This also demonstrates why Monday is not interchangeable with Mondays. The surrounding determiner or expression often tells you whether the noun should be singular or plural.

Do You Capitalize Monday?

Yes. Monday is capitalized because it is the name of a day of the week.

The same applies to:

• Tuesday
• Wednesday
• Thursday
• Friday
• Saturday
• Sunday

The capitalization remains when the word becomes plural or possessive:

• Mondays
• Monday’s
• Mondays’

The apostrophe does not change the capitalization of the underlying word.

What About Formal Writing?

All four forms can be grammatically useful, but their functions matter more than whether the writing is formal.

Mondays is perfectly normal in formal writing when you mean multiple Mondays:

Staff meetings are held on Mondays.

Monday’s is also standard when used as a possessive:

Monday’s meeting will begin at 10 a.m.

Contractions such as Monday’s = Monday is are more conversational and may be less suitable when a highly formal style calls for expanded forms. Cambridge notes that contractions are common in everyday speech and informal writing and are generally less appropriate in formal writing. ([Cambridge Dictionary][3])

For example:

Monday is expected to be busy.

is more formal than:

Monday’s expected to be busy.

The contraction is not inherently ungrammatical; the choice depends on the desired style.

Can the Same Rule Apply to Other Days?

Yes.

The same basic distinction applies to the other days of the week.

For example:

• Tuesday = one Tuesday
• Tuesdays = multiple Tuesdays
• Tuesday’s = singular possessive or contraction
• Tuesdays’ = plural possessive

The same pattern works with:

• Wednesday / Wednesdays / Wednesday’s / Wednesdays’
• Thursday / Thursdays / Thursday’s / Thursdays’
• Friday / Fridays / Friday’s / Fridays’
• Saturday / Saturdays / Saturday’s / Saturdays’
• Sunday / Sundays / Sunday’s / Sundays’

For example:

I work on Fridays.

But:

Friday’s meeting starts at noon.

And:

Friday’s going to be busy.

The underlying grammatical principle stays the same.

A Simple Way to Remember It

Think of the apostrophe as needing a job.

If you only want to make Monday plural, you do not need an apostrophe:

Monday → Mondays

If you want to show a relationship with one Monday:

Monday → Monday’s

Iff you want to show a relationship with multiple Mondays:

Mondays → Mondays’

Iff the apostrophe replaces missing letters in a contraction:

Monday is → Monday’s

So the basic pattern is:

Monday → one

Mondays → more than one

Monday’s → one + possession OR contraction

Mondays’ → more than one + possession

Once you understand that pattern, the spelling becomes much easier to choose from context.

Frequently Asked Questions

Is “Mondays” correct?

Yes. Mondays is the standard plural form of Monday. Use it when referring to multiple Mondays or Mondays as a recurring occurrence.

I work from home on Mondays.

Is “Monday’s” correct?

Yes, but only when its grammatical function supports the apostrophe. Monday’s can be a singular possessive or a contraction of Monday is or Monday has.

Is “Monday’s” the plural of Monday?

No. The plural is Mondays, without an apostrophe.

Monday → Mondays

An apostrophe should not normally be added simply to make a noun plural. ([Cambridge Dictionary][2])

Is “every Mondays” correct?

No, not in standard edited English. The usual form is every Monday.

I go to the gym every Monday.

Is “on Mondays” correct?

Yes. Use on Mondays when describing something that happens repeatedly on Mondays.

We have meetings on Mondays.

Is “on Monday” correct?

Yes. Use on Monday when referring to a particular Monday.

We have a meeting on Monday.

What is the plural possessive of Monday?

The plural possessive is Mondays’.

For example:

The two Mondays’ schedules were different.

Can “Monday’s” mean “Monday is”?

Yes.

Monday’s going to be busy.

Here, Monday’s means Monday is.

Can “Monday’s” mean “Monday has”?

Yes, when has functions as an auxiliary verb.

Monday’s been unusually quiet.

Here, Monday’s means Monday has.

Is “Mondays’” grammatically correct?

Yes. Mondays’ is the plural possessive form. It is appropriate when something is associated with multiple Mondays.

Should I write “Monday morning” or “Monday mornings”?

Both can be correct.

Use Monday morning for one particular Monday morning:

I called her Monday morning.

Use Monday mornings for recurring Monday mornings:

I exercise on Monday mornings.

Final Verdict: Mondays or Monday’s?

Mondays and Monday’s are both correct forms, but they serve different purposes.

Use Monday for one specific day:

I will call you Monday.

Use Mondays for multiple or recurring Mondays:

I work on Mondays.

Usee Monday’s for singular possession or for the contractions Monday is and Monday has:

Monday’s meeting starts at nine. Monday’s going to be busy.

Usee Mondays’ for plural possession:

The two Mondays’ schedules were different.

The most important rule to remember is this:

Do not use an apostrophe just because you want to make “Monday” plural. The plural is “Mondays.”

When you see Monday’s, ask whether the apostrophe shows possession or represents missing letters in a contraction. When you see Mondays’, ask whether something is associated with multiple Mondays.