إذا كانت عندنا دعوة أخرى في الشهر القادم، فسوف نطبخ طعاما لذيذا أيضا.

After إذا meaning if/when, Arabic often uses a past-tense verb to talk about a future condition.

So:

إذا كانت عندنا دعوة أخرى...

does not mean only if we had in a past sense. Here it means more like:

if we have / if there is / if we happen to have

This is a very common Arabic pattern:

• إذا جاء = if/when he comes
• إذا وصلنا = if/when we arrive

So the past form after إذا often has a future meaning in English.

Because the implied subject of كانت is دعوة (an invitation), and دعوة is a feminine singular noun.

Arabic verbs agree in gender, so:

• كان = masculine singular
• كانت = feminine singular

Since the sentence is structurally about دعوة أخرى (another invitation), the feminine form كانت is correct.

عندنا literally means at us or with us, but very often it is used to express having something.

So:

عندنا دعوة
literally: at us is an invitation
natural English: we have an invitation

In this sentence, كانت عندنا دعوة أخرى means we had / we would have / there was for us another invitation, depending on context. In smoother English, it is simply if we have another invitation.

Arabic often uses this kind of order in existence/possession expressions:

• عندنا كتاب = we have a book
• لديهم سيارة = they have a car

So instead of starting with the noun, Arabic commonly puts the phrase like عندنا first, then the thing possessed.

In this sentence:

• عندنا = with us / we have
• دعوة أخرى = another invitation

This word order sounds natural in Arabic.

In a fuller grammatical analysis, دعوة is the delayed ism kāna (the noun associated with كان), while عندنا functions as the predicate.

So the structure is roughly:

• كانت = was
• عندنا = with us
• دعوةٌ أخرى = another invitation

If fully vowelled, it would be:

إذا كانت عندنا دعوةٌ أخرى...

Notice that دعوةٌ would be nominative here.

Because أخرى is an adjective meaning other / another, and in Arabic adjectives normally come after the noun they describe.

So:

• دعوة أخرى = another invitation
• literally: invitation other

Also, the adjective must agree with the noun in:

• gender
• number
• definiteness
• case

Since دعوة is feminine singular and indefinite, أخرى matches it.

In Arabic, adjectives come after the noun.

So:

• الشهر = the month
• القادم = coming / next

Together: الشهر القادم = the coming month / next month

Also, because الشهر is definite with ال, the adjective must also be definite:

• الشهر القادم not
• الشهر قادم in this meaning

Both can mean if, but they are not used in exactly the same way.

A helpful general rule is:

• إذا often suggests a real, expected, or likely condition, often in the future
• إن is more general and can sound less definite or more hypothetical

So in this sentence, إذا fits well because the speaker is talking about a realistic future possibility: if we have another invitation next month...

In many contexts, learners will see some overlap, but إذا is very common for future time conditions.

The فـ here links the result clause to the condition. It is very common in conditional sentences.

So the pattern is:

إذا ... فـ...
if ... then ...

And since the answer to the condition begins with سوف, Arabic naturally says:

فسوف نطبخ...
= then we will cook...

So:

• إذا introduces the condition
• فـ introduces the result
• سوف marks the future

Together they give a very clear structure.

Because in Arabic, the present tense with سوف expresses the future.

So:

• نطبخ = we cook / we are cooking
• سوف نطبخ = we will cook

That is why Arabic does not need a separate future verb form the way English does. It uses the present stem plus a future marker such as سوف or سـ.

Because طعامًا is the direct object of نطبخ, so it is in the accusative case, and لذيذًا is its adjective, so it must match.

So:

• نطبخ طعامًا = we cook food
• طعامًا لذيذًا = delicious food

Both are:

• singular
• masculine
• indefinite
• accusative

That is why both take the accusative ending in full vocalization:

• طعامًا
• لذيذًا

أيضا means also / too / as well.

So the sentence is saying not just that we will cook delicious food, but that we will also cook delicious food.

Putting أيضا at the end is very natural in Arabic. It often works much like English too or as well at the end of a sentence.

Yes. عندنا and لدينا can both mean we have.

So you could also say:

إذا كانت لدينا دعوة أخرى في الشهر القادم، فسوف نطبخ طعاما لذيذا أيضا.

Very roughly:

• عندنا is very common and natural
• لدينا can sound a bit more formal or written

Both are correct in Modern Standard Arabic.