Misafirler gelmeden önce annem biraz telaşlı görünüyordu.

Before the guests arrived, my mother looked a little flustered.

Breakdown of Misafirler gelmeden önce annem biraz telaşlı görünüyordu.

• benim: my
• gelmek: to come
• görünmek: to look
• önce: before

Questions & Answers about Misafirler gelmeden önce annem biraz telaşlı görünüyordu.

How does gelmeden önce work?

It is made of:

• gel- = come / arrive
• -meden = without doing
• önce = before

By itself, gelmeden means without coming. But the fixed pattern -meden önce means before doing.

So misafirler gelmeden önce means before the guests arrived / before the guests came.

Turkish often uses this kind of non-finite structure where English would use a full clause.

Can gelmeden önce have a different subject from the main clause?

Yes. That is completely normal in Turkish.

In this sentence:

• misafirler are the ones who come/arrive
• annem is the one who looks anxious

So even though English learners may expect before arriving to refer to the same person as the main clause, Turkish can name a different subject clearly.

Why is misafirler in its plain form, with no extra case ending?

Because misafirler is the subject of the time clause.

It is the one doing the action of gelmek. Subjects are normally in the basic form, often called the nominative.

Compare:

• misafirler gelmeden önce = before the guests arrived
• misafirlerden önce = before the guests

The second one is a noun phrase with önce, so it takes -den. The first one is a verb-based clause, so it uses -meden önce instead.