Η μαμά μου γυαλίζει το περβάζι και μετά ανοίγει λίγο το παράθυρο να αεριστεί το δωμάτιο.

μου means my, but in Greek the unstressed possessive form usually comes after the noun:

η μαμά μου = my mom

That post-noun position is the normal, neutral pattern. Greek does have other word orders for emphasis, but η μαμά μου is what a learner should treat as the standard form.

Greek normally keeps the definite article with possessed nouns:

• η μαμά μου = my mom
• το σπίτι μου = my house
• ο φίλος μου = my friend

So Greek says something more like the mom my, even though natural English drops the.

Yes. μαμά is the everyday word for mom / mum. It sounds warm and natural in ordinary speech.

A more formal or neutral word is μητέρα, which means mother. So:

• η μαμά μου = my mom
• η μητέρα μου = my mother

In Greek, the present tense can describe:

• a habitual action
• something happening now
• a vivid step-by-step description

So this sentence could mean either a routine action or a narrated scene, depending on context. Greek uses the present here very naturally, just as English can in sentences like She polishes the sill and then opens the window a little.

γυαλίζει comes from γυαλίζω, which literally means make shiny. In this sentence it means something like:

• polishes
• shines
• wipes until clean/shiny

So the idea is that the mom is cleaning the windowsill so it looks polished or shiny.

Yes. γυαλί means glass, and the verb γυαλίζω is historically related to the idea of something becoming glossy or shiny like glass.

But in everyday use, γυαλίζω does not mean to glass something. It means to polish / make shine.

το περβάζι means the windowsill or the window ledge.

It is a neuter noun, which is why it takes το. In this sentence, it is the direct object of γυαλίζει.

Yes, μετά already has the idea of after / then / afterwards. But και μετά is a very common Greek combination meaning:

• and then
• and afterwards

Here, και links the two actions, and μετά shows the sequence.

Here λίγο means a little / slightly. So the idea is that she opens the window just a bit, not all the way.

In other contexts, λίγο can also mean for a short while, but in this sentence the most natural reading is degree: she opens it slightly.

Greek word order is more flexible than English word order. In ανοίγει λίγο το παράθυρο, the adverb λίγο naturally modifies the action opens:

she opens the window a little

This is a very normal placement. You may see other orders in Greek, but this one is straightforward and idiomatic.

να introduces a dependent verb form, usually called the subjunctive in Greek grammar.

Here it shows purpose:

ανοίγει λίγο το παράθυρο να αεριστεί το δωμάτιο
= she opens the window a little so that the room can air out

Modern Greek does not normally use an infinitive the way English does, so να + verb often does work that English expresses with to or so that.

Both are possible.

• να αεριστεί το δωμάτιο
• για να αεριστεί το δωμάτιο

για να is a bit more explicit and clearly means in order to / so that.
Plain να can also express purpose, especially in everyday speech after verbs like open, close, come, go, and similar actions.

So the sentence sounds natural as written.

αεριστεί is the 3rd person singular aorist subjunctive, passive/middle voice form of αερίζω / αερίζομαι.

That sounds technical, but the important part is this:

• να αεριστεί = so that it gets aired / so that it airs out

The aorist here does not mean past tense. After να, Greek uses aspect rather than tense in the usual English sense. The aorist presents the action as a single whole result: the goal is for the room to become aired out.

It is the subject of αεριστεί.

The room is the thing that gets aired out:

να αεριστεί το δωμάτιο = so that the room can air out / be aired

Greek often places the subject after the verb, especially in clauses like this. That is perfectly normal.

Also, το δωμάτιο looks the same in nominative and accusative because it is neuter singular, so form alone does not tell you its role here. The meaning of the clause does.

It can do either, depending on context.

Without extra context, the present tense can mean:

• a routine action: Mom usually polishes the sill and then opens the window a little
• a live description: Mom is polishing the sill and then opening the window a little

So a Greek learner should not assume that present tense automatically means only right now.