Si le délai change encore, Marie appellera demain matin.

Because after si meaning if, French normally uses the present tense, not the future, when talking about a real possible condition.

So French says:

• Si le délai change encore, Marie appellera demain matin.

Literally, this is structured like:

• If the deadline/schedule changes again, Marie will call tomorrow morning.

Even though the meaning is future, the verb after si stays in the present: change.

A very common mistake for English speakers is to copy English and say si ... changera. Standard French does not do that here.

A useful pattern to remember:

• si + present, future
• Si tu viens, je partirai.
• Si elle appelle, nous répondrons.

Here, si means if.

It introduces a condition:

• Si le délai change encore = If the schedule/deadline changes again

This is different from:

• quand = when
• oui = yes
• si can also mean whether in other contexts, but not here

In this sentence, si clearly sets up a condition: Marie will call only in the situation where the deadline changes again.

Not exactly. Le délai is a tricky word for English speakers because it looks like delay, but it usually means something more like:

• deadline
• time limit
• time frame
• allowed period
• sometimes schedule/timing, depending on context

So le délai is often a false friend. It does not usually mean the act of something being late.

For example:

• un délai de trois jours = a three-day time limit / a period of three days
• le délai de livraison = delivery time / delivery deadline

In your sentence, le délai change encore likely means something like:

• the deadline changes again
• the time frame changes again
• the schedule shifts again

The exact English translation depends on context.

Encore often means again or still, depending on context.

In this sentence:

• Si le délai change encore
  means
• If the deadline changes again

So here encore means again.

That suggests the deadline has already changed before, and it may change one more time.

Compare:

• Il mange encore. = He is still eating.
• Dis-le encore. = Say it again.

So encore can have more than one meaning, and context tells you which one fits.

Appellera is the simple future form of appeler.

• appeler = to call
• elle appellera = she will call

French uses the future here because the calling will happen later, after the possible change in the deadline.

This fits the standard conditional pattern:

• Si + present, then future

So:

• Si le délai change encore, Marie appellera demain matin.

You could think of it as:

• condition now or in the future → result in the future

Yes, that is possible in many contexts.

• Marie appellera demain matin = simple future
• Marie va appeler demain matin = near future / going to call

Both can refer to the future, but there is a slight difference in feel:

• appellera sounds a bit more neutral, standard, or written
• va appeler can sound a bit more immediate or conversational

So a sentence like this would also be natural:

• Si le délai change encore, Marie va appeler demain matin.

But the original version with appellera is completely normal and often preferred in formal or neutral written French.

French time expressions often do not use an article in set expressions like this.

• demain = tomorrow
• demain matin = tomorrow morning

So French simply says:

• demain matin not
• le demain matin

Other common examples:

• ce matin = this morning
• hier soir = last night / yesterday evening
• demain après-midi = tomorrow afternoon

This is just the normal fixed expression.

Yes. You can put the main clause first or the si clause first.

Original:

• Si le délai change encore, Marie appellera demain matin.

Also possible:

• Marie appellera demain matin si le délai change encore.

Both mean the same thing.

The difference is mostly about style or emphasis:

• starting with Si... highlights the condition first
• putting it at the end lets the statement come first

When the si clause comes first, a comma is commonly used in writing. When it comes second, the comma is often omitted.

The comma separates the introductory si clause from the main clause.

• Si le délai change encore, Marie appellera demain matin.

This is very common in writing when the conditional clause comes first.

If you reverse the order, you usually do not need the comma:

• Marie appellera demain matin si le délai change encore.

So the comma is mainly about sentence structure and readability.

Appellera comes from appeler.

The spelling has two ls because of how this verb changes in some forms. French spelling keeps that pattern in the future stem:

• appeler
• j’appelle
• il appellera

The rough pronunciation is:

• ah-pehl-ruh

The final a in appellera is not pronounced like the English a in cat. It sounds more like a neutral ending.

For an English speaker, the important point is that:

• appellera = one written word meaning will call
• it is not split into separate words the way English uses will call

It normally means sometime tomorrow morning.

• demain matin gives the time frame
• it does not usually mean an exact moment

So the sentence means that, if the deadline changes again, Marie’s call will happen during tomorrow morning.

If French wanted to be more precise, it could say something like:

• à 9 heures demain matin = at 9 tomorrow morning
• dès demain matin = as early as tomorrow morning / starting tomorrow morning

So the original sentence is specific about the part of the day, but not about the exact hour.