אני גרה בקומה השנייה, והשכנה גרה בקומה הראשונה.

It is hidden inside בקומה. Hebrew often combines a preposition with ה־ (the). So here you can think of it as:

ב + ה + קומה → בקומה

In pointed Hebrew, this would be pronounced ba-koma, not just be-koma. So the phrase means on the second floor, not just on a second floor.

Because in Hebrew, adjectives usually come after the noun. Ordinal numbers like ראשון / שני / שלישי behave like adjectives in this kind of phrase.

So:

• קומה השנייה = the second floor
• literally: floor the-second

This noun-then-adjective order is very common in Hebrew.

Because קומה is a feminine noun, and adjectives/ordinals must agree with the noun in gender and number.

So you get:

• קומה ראשונה
• קומה שנייה

If the noun were masculine, you would use masculine forms:

• החדר הראשון
• החדר השני

Hebrew first is irregular, just as English first is not built directly from one. The masculine form is ראשון, and the feminine form is ראשונה.

By contrast, second is שני / שנייה, which is more clearly related to the number two historically. So ראשונה is just the normal Hebrew word for first.

השכנה means the female neighbor. Hebrew distinguishes gender here:

• שכן = male neighbor
• שכנה = female neighbor

In English, the translation may simply say the neighbor, but the Hebrew form tells you that the neighbor is a woman.

Repeating the verb is completely natural in Hebrew and makes the sentence clear and balanced:

אני גרה בקומה השנייה, והשכנה גרה בקומה הראשונה.

You could also omit the second גרה in some contexts:

אני גרה בקומה השנייה, והשכנה בקומה הראשונה.

That is also understandable, but the full version is very standard.

It can cover both, depending on context. Hebrew present tense often does the work of both the English simple present and present progressive.

So אני גרה can mean:

• I live
• I am living

In this sentence, the natural meaning is the regular, habitual one: I live.

Usually not exactly. In Israeli usage, קומת קרקע is the ground floor, and קומה ראשונה is the floor above that. So it works more like British English floor numbering than American English.

So in many real-life situations:

• קומת קרקע = ground floor
• קומה ראשונה = first floor above ground

This is useful to know when talking about buildings in Hebrew.