themselves
The Italian translation for 'themselves' is 'loro stessi'. It is used in the same context as in English, mainly to refer back to the subject of the clause, when the subject is plural. It's a reflexive pronoun, often used to indicate that the subject of the verb is performing the action on themselves.
They must solve the problem themselves.
This sentence uses 'loro stessi' to emphasize that the subject of the sentence, 'they', must solve the problem on their own, without the assistance of others. It is used to stress the responsibility or effort of the subject.
They cooked the dinner themselves.
In this instance, 'loro stessi' is used to express that 'they' completed the action of cooking the dinner on their own. It implies a sense of accomplishment and personal involvement in the task.
They should be proud of themselves.
This sentence uses 'loro stessi' in relation to the subject being proud. In English, we use themselves to reflect the action of the verb back onto the subject, in this case highlighting that the pride referred to is self-pride.