لازم ننضف الستارة قبل ما الضيوف يجوا.

لازم expresses necessity. In this sentence, it means something like must, have to, or need to.

So لازم ننضف... = we have to clean...

It is a very common Egyptian Arabic way to talk about obligation.

Because the verb itself already shows the subject.

In ننضف, the prefix نـ tells you the subject is we.

So Arabic does not need a separate pronoun here.
If you wanted extra emphasis, you could say إحنا لازم ننضف الستارة = we have to clean the curtain, but normally إحنا is omitted.

Because this is not a direct command to you. It is a statement about what we need to do.

In Egyptian Arabic:

• نضف! = Clean! (command to one person)
• ننضف = we clean / we should clean / we need to clean

After لازم, Arabic normally uses the imperfect verb, so لازم ننضف is the natural structure.

In Egyptian Arabic, بـ often marks the ordinary present or habitual:

• بننضف = we clean / we are cleaning
• بيجوا = they come / they usually come

But after لازم, the verb is usually used without بـ:

• لازم ننضف = we have to clean

And after قبل ما, the verb often appears without بـ because it refers to a future event:

• قبل ما الضيوف يجوا = before the guests come

So the lack of بـ is normal here.

قبل ما means before when followed by a full clause.

So:

• قبل = before
• قبل ما الضيوف يجوا = before the guests come

Here, ما is not a negative word. It is just part of the expression قبل ما.

الستارة means the curtain.

The الـ is the definite article, equivalent to English the.

• ستارة = a curtain
• الستارة = the curtain

So the sentence is specifically talking about a particular curtain, not just any curtain.

It is singular: the curtain.

If you wanted the curtains, you would usually say الستاير in Egyptian Arabic.

So this sentence is about one curtain, or one curtain being treated as a single item.

Because الضيوف means the guests, which is a human plural noun.

So the verb agrees with it:

• الضيف ييجي = the guest comes
• الضيوف يجوا / ييجوا = the guests come

With human plurals, plural agreement is normal.

It comes from the verb ييجي = he comes.

Common forms are:

• ييجي = he comes
• تييجي = she comes / you come
• يجوا / ييجوا = they come

The ending ـوا marks the plural they.

Also, in informal writing, both يجوا and ييجوا can be used. They represent the same word.

A natural pronunciation would be roughly:

lāzem ننضف is usually said with a doubled middle consonant, and يجوا is pronounced like yigū

Also, the الـ in الستارة and الضيوف assimilates in speech because س and ض are sun letters, so you hear something closer to:

• الستارة → es-setāra
• الضيوف → eḍ-ḍuyūf

So the whole sentence sounds more like:

lāzem n-naḍḍaf es-setāra ʔabl ma eḍ-ḍuyūf yigū

Not necessarily.

ننضف means clean in a general sense. For a curtain, that could mean:

• dusting it
• wiping it
• freshening it up
• cleaning it in whatever way makes sense

If you specifically wanted to say wash the curtain, نغسل الستارة would be more precise.

So ننضف is broader than wash.