This is the 496th most frequent Italian word.
dover
"Dovere" in Italian means "must," "to have to," or "duty."
Here, 'devo' is the first person singular conjugation of 'dovere' and is used to express a duty or necessity.
Devo studiare italiano ogni giorno.
I must study Italian every day.
'Dovuto' is the past participle of 'dovere' used in a past tense form with 'hanno' to indicate an obligation that occurred in the past.
Hanno dovuto lasciare la festa presto.
They had to leave the party early.
The conditional form 'dovresti' suggests advisability or recommendation.