Ça t’embête si je commande une omelette au lieu d’un sandwich ?

Literally, ça means that / it, and embêter means to bother, annoy, inconvenience.

So Ça t’embête ? is literally something like:

Does that bother you?
or
Is that a problem for you?

In this sentence, it is a natural way to ask whether the other person minds something.

T’ is just the shortened form of te before a vowel sound.

• te embête would be awkward in French
• so it becomes t’embête

This is called elision.

You see the same thing in many common phrases:

• je aime → j’aime
• te appelle → t’appelle
• le ami → l’ami

So Ça t’embête = Ça te embête, but only the shortened form is correct.

Because the subject of the verb is ça, not tu.

In Ça t’embête:

• ça = the thing that is bothering
• t’ = you, as the object
• embête = 3rd person singular, matching ça

So the structure is:

That bothers you

not

You bother

That is why the verb is embête, not embêtes.

French often forms questions just by using statement word order with rising intonation in speech.

So all of these can work:

• Ça t’embête si je commande une omelette ?
• Est-ce que ça t’embête si je commande une omelette ?
• Ça t’embête si je commande une omelette au lieu d’un sandwich ?

The version in your sentence is very natural and common in everyday spoken French.

It is less formal than inversion, such as:

• Cela t’embête-t-il si je commande... ?

That last version is grammatical, but much more formal and much less common in ordinary conversation.

It can mean to annoy, but in a sentence like this it usually means something softer, like:

• to bother
• to inconvenience
• to be a problem for

So Ça t’embête si... ? often means:

Do you mind if...?

It is a very common, natural phrase and not rude.

A close synonym is:

• Ça te dérange si... ? = Would it bother you / Do you mind if...?

Both are common.

Here si means if, and after this kind of si, French normally uses the indicative, not the subjunctive.

So:

• si je commande = if I order

This is a real, possible action, so the present indicative is the normal choice.

French does not say:

• si je commande with subjunctive meaning — that would be wrong here

Also, English sometimes uses if I ordered in more hypothetical contexts, but here French is simply asking about a real possible action in the present situation, so je commande is exactly what you expect.

Yes, but it changes the tone.

• si je commande sounds more direct and practical: if I order
• si je commandais sounds more tentative or hypothetical: if I were to order

So:

• Ça t’embête si je commande une omelette ? = natural, straightforward
• Ça t’embêterait si je commandais une omelette ? = more cautious, softer

Both are possible, but your original sentence is completely normal.

Au lieu de means instead of or more literally in the place of.

It comes from:

• à + le lieu de → au lieu de

So au is the contraction of à le.

Examples:

• au lieu d’un sandwich = instead of a sandwich
• au lieu de partir = instead of leaving

This is a fixed expression, so it is best learned as a chunk:

au lieu de

Because de contracts with un? Actually, it does not contract with un in the same way that à + le becomes au. What is happening here is simpler:

• de un sandwich is not the normal form
• French uses d’un sandwich

So after au lieu de, when the next word begins with a vowel sound, de becomes d’ by elision:

• de + un sandwich → d’un sandwich

Compare:

• au lieu d’un sandwich
• au lieu de la salade
• au lieu des frites

Because French nouns have grammatical gender.

• omelette is feminine → une omelette
• sandwich is masculine → un sandwich

This is something you simply have to learn with each noun.

A good habit is to memorize nouns with their article:

• une omelette
• un sandwich

not just omelette and sandwich by themselves.

Yes.

• Ça t’embête si... ?
• Cela t’embête si... ?

Both are grammatical.

But ça is much more common in everyday spoken French.
Cela sounds a bit more formal, careful, or written.

So in normal conversation, ça is the natural choice.

Yes, it is polite and natural.

Ça t’embête si je commande une omelette au lieu d’un sandwich ? is a normal way to ask whether someone minds your choice.

If you want to sound even softer or more polite, you could say:

• Ça t’embêterait si je commandais une omelette au lieu d’un sandwich ?
• Ça te dérangerait si je commandais une omelette au lieu d’un sandwich ?

Those versions are more tentative, a bit like Would you mind if... ?

Your original sentence is already perfectly acceptable and polite in everyday conversation.

In natural speech, it sounds roughly like:

sa tam-bet see zhuh koh-mahnd uhn awm-let oh lyuh dun sahn-dweech

A few useful pronunciation points:

• Ça sounds like sa
• t’embête links smoothly together
• je is often pronounced very lightly
• au lieu d’un flows together quite a lot in fast speech
• sandwich in French is usually pronounced more like sahn-dweech than the English pronunciation

You do not need to pronounce every word separately in a choppy way; native speech connects them smoothly.