This is the 3433rd most frequent Catalan word.
ells
"They" (masculine or mixed-gender plural).
In this case, 'ells' is used as the subject pronoun to refer to a group of people in the third person plural.
Ells són molt amables.
They are very kind.
Here, 'ells' is used as an object pronoun to refer to a group of people in the third person plural, functioning as the direct object of the verb.
He vist a ells al parc.
I saw them in the park.
In this sentence, 'ells' is used as the object pronoun in the third person plural and is the object of the preposition 'amb' (with).