J’aurais dû mettre une virgule dans mon message à la professeure.

J’aurais dû is the conditional perfect of devoir.

It is built like this:

• aurais = conditional of avoir
• dû = past participle of devoir

So:

• je dois = I must / I have to
• je devais = I had to / I was supposed to
• j’ai dû = I had to / I must have
• j’aurais dû = I should have / I ought to have

In this sentence, j’aurais dû mettre... means I should have put...

Because the speaker is expressing a regret or missed obligation, not simply a hypothetical past action.

• j’aurais mis une virgule = I would have put a comma
• j’aurais dû mettre une virgule = I should have put a comma

So devoir adds the idea of “it was the right thing to do” or “I was supposed to do it.”

The circumflex helps distinguish dû from du.

• du = contraction of de le, or partitive article
• dû = past participle of devoir

Examples:

• J’ai acheté du pain. = I bought some bread.
• J’aurais dû écrire. = I should have written.

In modern French, some circumflex accents are optional in certain words, but dû is normally kept because it helps avoid confusion.

Yes. Mettre une virgule is a very natural way to say to put a comma.

Other possible verbs exist depending on context, but mettre is the most straightforward and idiomatic here.

For punctuation, French commonly uses:

• mettre un point = put a period/full stop
• mettre une virgule = put a comma
• ajouter une virgule = add a comma

So this part of the sentence is completely normal.

Because the comma is understood as something inside the text of the message, not physically on top of an object.

• dans mon message = in my message
• sur mon message would sound less natural here

French usually treats punctuation as part of the written content, so dans is the expected preposition.

Yes. Here à marks the recipient of the message.

• un message à quelqu’un = a message to someone

So:

• mon message à la professeure = my message to the teacher/professor

This is different from English, where to is clearly required. In French, à often fills that role.

You could also say:

• un message pour la professeure

But à la professeure is very natural when you mean the person who received or was meant to receive the message.

Because professeure is the feminine form used for a female professor/teacher.

Common possibilities are:

• le professeur = male professor / teacher
• la professeure = female professor / teacher

Depending on region and style, you may also see:

• la professeur
• la professeure
• sometimes la prof

In much modern French, especially in inclusive or contemporary usage, professeure is widely accepted and common.

It depends on context.

In French, professeur / professeure can refer to:

• a school teacher
• a high school teacher
• a university professor

So the exact English translation depends on who this person is. If the meaning has already been given to the learner, then the key thing to understand is that French uses the same base word more broadly than English sometimes does.

Because je becomes j’ before a vowel sound.

Since aurais begins with au-, French contracts:

• je aurais ❌
• j’aurais ✅

This is very common:

• j’ai
• j’aime
• j’écris
• j’aurais

It makes pronunciation smoother.

Yes, there is a difference, although it can be subtle for learners.

• j’aurais dû = conditional
• j’aurai dû = future perfect

In careful pronunciation:

• aurais often sounds like or-eh
• aurai often sounds like or-ay

So:

• j’aurais dû ≈ zho-reh du
• j’aurai dû ≈ zho-ray du

In everyday speech, some speakers pronounce them very similarly, so context often helps.

In j’aurais dû mettre, dû is followed by an infinitive (mettre), and in this kind of structure it normally stays unchanged.

That is because the real action is mettre une virgule, and dû functions with that infinitive rather than agreeing with virgule.

So:

• J’aurais dû mettre une virgule. ✅
• not due here ❌

This is a point that often confuses learners, but the short answer is: with devoir + infinitive, the past participle usually stays dû.

Yes, but it means something slightly more specific.

• dans mon message à la professeure = in my message to the professor
• dans my message envoyé à la professeure = in my message sent to the professor

The longer version emphasizes that the message was actually sent. The original sentence is lighter and more natural unless you specifically want to stress that point.

It is generally neutral.

• message can refer to a text, email, DM, or other written note depending on context.
• à la professeure sounds normal and respectful.
• The overall sentence sounds like natural spoken or written French.

If you wanted something more casual, you might hear:

• J’aurais dû mettre une virgule dans mon message à la prof.

If you wanted something more formal, you might specify the type of message:

• J’aurais dû mettre une virgule dans mon courriel à la professeure.