Kapı açık olduğuna göre, arkadaşım eve gelmiş olmalı.

Since the door is open, my friend must have come home.

Breakdown of Kapı açık olduğuna göre, arkadaşım eve gelmiş olmalı.

• olmak: to be
• ev: the house
• benim: my
• arkadaş: the friend

Questions & Answers about Kapı açık olduğuna göre, arkadaşım eve gelmiş olmalı.

Why is there no verb in Kapı açık?

In Turkish, a present-tense sentence with a noun or adjective predicate often has no separate verb.

So:

• Kapı = the door
• açık = open

Together, Kapı açık simply means The door is open.

English needs is, but Turkish usually leaves that copula unspoken in the present tense.

Compare:

• Kapı açık. = The door is open.
• Kapı açıktı. = The door was open.
• Kapı açık olacak. = The door will be open.

So the lack of a word for is here is completely normal.

What does olduğuna göre mean in this sentence?

...olduğuna göre is a very common pattern meaning something like:

• given that ...
• since ...
• considering that ...
• if that is the case ...

So:

• Kapı açık olduğuna göre = Since the door is open / Given that the door is open

It introduces the reasoning basis for the conclusion in the second part of the sentence.

The speaker is thinking:

1. The door is open.
2. Therefore, my friend must have come home.

So this expression is often used for logical deduction.

How is olduğuna göre built grammatically?