This is the 12243rd most frequent Turkish word.
hakikatı
"The truth" or "reality."
In this sentence, 'hakikatı' refers to 'the truth' in a general sense. It is the object of the verb 'öğrenmek' (to learn).
Hakikatı öğrenmek için çok çalışmalısınız.
You must work hard to learn the truth.
Here, 'hakikatı' is used possessively ('onun' - his) and refers to a personal interpretation or understanding of the truth.
Onun hakikatı her zaman güvenilir olmuştur.
His truth has always been reliable.
In this sentence, 'hakikatı' denotes 'the truth' as something that one might conceal, and serves as the object of the verb 'saklamak' (to hide).