This is the 850th most frequent Lithuanian word.
jus
The Lithuanian word "jūs" means "you" (formal or plural).
The word "jumis" in this sentence is the instrumental case of "jus," used to express the means through which trust is facilitated towards the addressed individuals.
Ar galiu jumis pasitikėti?
Can I trust you?
Here, "jus" is directly the accusative case, the standard form to denote the direct object of the verb "to see."
Aš matau jus parke.
I see you in the park.
In this sentence, "jūsų" is the genitive case of "jus," used to show possession, indicating that the reply belongs to the addressed individuals.