Η πόρτα που ανοίγεις δεν κλείνει καλά.

well

Breakdown of Η πόρτα που ανοίγεις δεν κλείνει καλά.

• δεν: not
• που: that
• κλείνω: to close

Questions & Answers about Η πόρτα που ανοίγεις δεν κλείνει καλά.

What is the function of the word που in this sentence?

που introduces a defining relative clause, equivalent to English that/which/who. Here it links η πόρτα to the clause ανοίγεις: “the door that you (are) opening.” It is invariable (no gender/case/number changes), and the “gap” it creates is the direct object of ανοίγεις inside the relative clause.

Why isn’t there a comma before που?

Because this is a defining (restrictive) relative clause: it specifies which door we mean. Greek does not use a comma before που in such clauses. With a non-defining clause you would normally prefer the inflected relative η οποία and set it off with commas: Η πόρτα, την οποία ανοίγεις, …

Should που have an accent (as πού) here?

No. πού (with accent) means “where?” (interrogative). που (without accent) is the relative/complementizer “that/which/who.” In this sentence it must be the unaccented που.

Why is there no εσύ (“you”) before ανοίγεις?

Modern Greek is a “pro‑drop” language: subject pronouns are usually omitted because the verb ending shows the person/number. ανοίγεις ends in ‑εις, which already tells us “you (sg) open/are opening.”

How do the verb endings show who is doing the action here?