This is the 119th most frequent Greek word.
ό
The Greek word "ό" is the masculine singular definite article, meaning "the" in English.
In this sentence, 'ό,τι' is a conjunction or pronoun used to refer to an unspecified thing, acting as 'whatever' or 'that which' in English.
Το βιβλίο ό,τι ψάχνεις είναι εδώ.
The book that you are looking for is here.
Here, 'Όταν' means 'When', indicating a temporal context — it introduces the relative clause.
Όταν ήρθες, το δωμάτιο ήταν άδειο.
When you came, the room was empty.
In this example, 'Όλα' means 'All', referring to inclusivity or entirety.