المدعو يصل اليوم مع بطاقة الدعوة.

Yes. المدعو is related to the verb دعا, which can mean to invite or to call.

Here, المدعو is the passive participle, so it literally means the one who has been invited/called. In this sentence, the natural meaning is the invited person or the invitee.

A useful warning: in other contexts, المدعو can also mean the so-called, so context is important.

Arabic يصل is in the imperfect tense, and that tense is broader than the English present tense.

Depending on context, يصل can mean:

• arrives
• is arriving
• sometimes even will arrive

Because the sentence includes اليوم (today), the meaning is naturally something like arrives today or is arriving today.

Arabic does not need a separate word for is arriving the way English does.

Yes, Arabic can say both:

• المدعو يصل اليوم...
• يصل المدعو اليوم...

Both are grammatical.

When the sentence starts with المدعو, it feels more like the invited person — he arrives today.... In grammar terms, many teachers analyze this as a nominal sentence with a verbal clause as its predicate.

When the verb comes first, يصل المدعو..., it is a more straightforward verbal sentence: The invited person arrives...

The basic meaning is the same, but the noun-first version gives a little more emphasis or topical focus to المدعو.

With full vowels, the sentence would be:

المدعوُّ يصلُ اليومَ مع بطاقةِ الدعوةِ

Here is why:

• المدعوُّ: nominative, because it is the subject/topic
• يصلُ: imperfect indicative
• اليومَ: accusative, because it functions as an adverb of time
• بطاقةِ: genitive, because it comes after مع
• الدعوةِ: genitive, because it is the second noun in an iḍāfa construction

In normal Arabic writing, these short vowel endings are usually omitted.

Because اليوم here is functioning as an adverb of time, called ظرف زمان.

So يصل اليوم simply means he arrives today.

Arabic often uses time expressions directly like this, without a preposition. The word is understood adverbially. With full case marking, it is اليومَ.

Because this is an iḍāfa construction, often called a possessive or noun-link construction.

بطاقة الدعوة literally means card of the invitation, which in natural English becomes the invitation card.

In an iḍāfa:

• the first noun usually does not take ال
• the first noun also does not take tanwīn
• the definiteness of the whole phrase depends on the second noun

So:

• بطاقة الدعوة = the invitation card
• بطاقة دعوة = an invitation card

Yes. الدعوة is also from the root د ع و.

Here it means the invitation. So:

• دعوة = invitation
• بطاقة الدعوة = invitation card

The root has a general idea of calling or inviting, so different related words can develop from it.

Because د is a sun letter.

When ال comes before a sun letter, the ل sound assimilates to the next consonant. So:

• written: الدعوة
• pronounced: ad-daʿwa

The spelling stays the same, but the pronunciation changes.

مع means with in the sense of accompanied by or having something with you.

So مع بطاقة الدعوة means the person arrives with the invitation card.

This is a very natural way in Arabic to express that someone has something in their possession when arriving.