לפני שהאורחים באים, אנחנו מקשטים את הסלון בבלונים ובנרות.

לפני ש־ means before when it introduces a whole clause.

• לפני by itself means before
• ש־ means something like that and connects it to the next clause

So:

• לפני האורחים = before the guests
• לפני שהאורחים באים = before the guests come

In Hebrew, ש־ is often attached directly to the following word, which is why you see שהאורחים as one written unit.

Here באים is present tense because the sentence is describing a habitual/repeated situation:

• Before the guests come, we decorate the living room...

This is similar to English using the present in general statements:

• Before guests come, we decorate...

Hebrew often uses the present tense for routines, habits, and general truths.

If you wanted to talk about one specific future event, Hebrew would more often use the future:

• לפני שהאורחים יבואו, נקשט את הסלון...
• Before the guests come, we will decorate the living room...

So in your sentence, the present suggests something more general or customary.

את marks a definite direct object.

In this sentence:

• הסלון = the living room
• because it is definite (the living room), Hebrew uses את before it

So:

• אנחנו מקשטים את הסלון = we decorate the living room

Important:

• את usually does not have a separate meaning you translate into English
• it is a grammatical marker

Compare:

• אני רואה ילד = I see a boy
• אני רואה את הילד = I see the boy

The prefix ה־ is the Hebrew definite article, meaning the.

So:

• סלון = living room
• הסלון = the living room

Hebrew usually adds ה־ directly to the beginning of the noun instead of using a separate word like English the.

Here ב־ means with in the sense of using something as a decorating material.

So:

• בבלונים = with balloons
• ובנרות = and with candles

The sentence:

• מקשטים את הסלון בבלונים ובנרות means:
• decorate the living room with balloons and candles

This use of ב־ is very common in Hebrew with verbs like:

• למלא במים = to fill with water
• לקשט בפרחים = to decorate with flowers

So it does not mean in balloons here; it means using balloons.

Because the word נרות also needs the prefix ב־.

You have:

• בבלונים = with balloons
• ובנרות = and with candles

The ו־ means and, and it joins onto the word that already has ב־:

• ו + ב + נרות → ובנרות

So the structure is:

• with balloons and with candles

Hebrew often repeats the preposition this way.

Yes, Hebrew can often leave subject pronouns out because the verb already shows the person and number.

• מקשטים already tells you it is we or they, depending on context
• so אנחנו מקשטים and מקשטים can both be possible

However, אנחנו is often included for clarity or emphasis.

So:

• אנחנו מקשטים את הסלון... = clear, natural, explicit we decorate...
• מקשטים את הסלון... = also possible, depending on context

מקשטים is the present tense masculine plural form of לקשט (to decorate).

It agrees with the subject:

• אנחנו = we

In Hebrew present tense, plural forms also reflect gender:

• מקשטים = masculine plural
• מקשטות = feminine plural

A mixed group, or a group of unspecified gender, normally uses the masculine plural form.

So this sentence suggests:

• either a masculine group
• or a mixed group
• or simply the default plural form

אורחים is the masculine plural form of guest:

• אורח = male guest
• אורחים = male guests / mixed guests

If all the guests were female, you would use:

• אורחות

So:

• האורחים = the guests (masculine or mixed)
• האורחות = the female guests

Hebrew uses masculine plural as the default for mixed groups.

Yes. Hebrew often places the time clause first, just like English can:

• לפני שהאורחים באים, אנחנו מקשטים את הסלון...
• Before the guests come, we decorate the living room...

This is very natural.

You could also put the main clause first:

• אנחנו מקשטים את הסלון בבלונים ובנרות לפני שהאורחים באים

That also makes sense:

• We decorate the living room with balloons and candles before the guests come

So the word order is flexible, but putting לפני... first emphasizes the timing.

Yes. Hebrew present tense often covers several English meanings, depending on context.

באים can mean:

• come
• are coming
• sometimes even a habitual usually come

In this sentence, because of לפני ש־ and the general context, English usually translates it as:

• Before the guests come...

But in another context, האורחים באים could also mean:

• The guests are coming

So Hebrew present tense is a bit broader than English present tense.

Here are the main dictionary forms:

• לפני = before
• אורח = guest
• לבוא = to come
• אנחנו = we
• לקשט = to decorate
• סלון = living room
• בלון = balloon
• נר = candle

And here are the forms used in the sentence:

• האורחים = the guests
• באים = come / are coming
• מקשטים = decorate
• הסלון = the living room
• בבלונים = with balloons
• בנרות = with candles