This is the 7521st most frequent Polish word.
krystynie
"Krystynie" is the dative form of "Krystyna," a Polish female name, meaning "to Krystyna" or "for Krystyna."
Here, 'krystynie' is used in the dative case, as it refers to the person Krystyna being the indirect object (the recipient of thanks).
Dziękuję krystynie za pomoc.
I thank Krystyna for her help.
In this sentence, 'krystynie' is used in the instrumental case, denoting the person Krystyna as the entity with whom the action of meeting occurred.
Spotkałem się z krystynie wczoraj.
I met with Krystyna yesterday.
'Krystynie' again appears in the dative case, indicating Krystyna as the recipient of something, which is the present in this context.