L’assemblée générale est demain.

Because la becomes l’ before a vowel sound. This is called elision.

• la assemblée would sound awkward in French
• so it changes to l’assemblée

You do the same with many common words:

• l’école instead of la école
• l’amie instead of la amie

Since assemblée is feminine, the full article is la, but before the vowel a-, it becomes l’.

Yes, assemblée is feminine.

A few clues help:

• the dictionary form is une assemblée
• many nouns ending in -ée are feminine, though not all endings are perfect rules
• the adjective générale also shows it is feminine, because it ends in -e

So the phrase is:

• une assemblée générale
• l’assemblée générale

Because adjectives usually agree with the noun they describe in gender and number.

Here:

• assemblée = feminine singular
• so général must become générale = feminine singular

Compare:

• un accord général = a general agreement
• une assemblée générale = a general assembly / general meeting

So the extra -e marks the feminine form.

In French, many adjectives come after the noun, unlike in English.

So:

• assemblée générale
• literally: assembly general
• natural English: general assembly or general meeting

Some French adjectives come before the noun, but many descriptive or classifying adjectives come after it. In this case, générale normally follows assemblée.

Because French often uses demain directly after être to mean is tomorrow.

So:

• Le rendez-vous est demain
• L’examen est demain
• L’assemblée générale est demain

You do not need a preposition here.

English also does something similar:

• The meeting is tomorrow

French can also say a lieu demain in some contexts, but est demain is simple and natural.

Yes, but the meaning changes slightly because the focus changes.

• L’assemblée générale est demain = The general meeting is tomorrow
• C’est demain = It’s tomorrow

C’est demain only works when everyone already knows what it refers to. On its own, it is less specific. The original sentence is clearer because it names the event directly.

It usually means general meeting or general assembly, depending on context.

Common uses include:

• a meeting of all members of an organization
• a company shareholders’ meeting
• an association’s annual or official general meeting

So the exact English translation depends on the situation, but general meeting is often the most natural everyday choice.

A careful pronunciation would be roughly:

la-san-blay zhay-nay-ral eh duh-man

A more helpful breakdown:

• L’assemblée ≈ la-san-blay
• générale ≈ zhay-nay-ral
• est ≈ eh
• demain ≈ duh-man

A few pronunciation notes:

• g in générale sounds like the s in measure
• the final -ée in assemblée sounds like ay
• demain has a nasal vowel at the end; the n is not fully pronounced like an English n

Normally, no important liaison is made between générale and est in everyday speech.

You may hear:

• l’assemblée générale est demain

without a strong linking sound there.

Also, with est demain, there is no liaison either.

So for a learner, the safe approach is simply to pronounce each part clearly without forcing extra linking consonants.

Yes, grammatically you could, but it is usually less natural here.

• est demain is the most straightforward way to say that a scheduled event happens tomorrow
• sera demain is possible, but it can sound a bit more formal, emphatic, or less idiomatic depending on context

In everyday French, for scheduled events, être + time expression is very common:

• Le match est demain
• La réunion est lundi
• L’assemblée générale est demain

Yes. You can say:

• Demain, l’assemblée générale est prévue
• Demain, c’est l’assemblée générale
• L’assemblée générale est demain

But L’assemblée générale est demain is a very natural neutral sentence.

If you move demain to the front, you often add a slight emphasis on the time:

• Tomorrow, the general meeting is happening

So the original word order is simple and standard.