A formal expression of thanksgiving
I thank thee
The formation hanta-nye-l is problematic. It comes from a time when most Neo-Quenya writers assumed that there are object suffixes for all persons. However Tolkien tells us:
The inflexions are subjective but -s (singular), -t (plural, dual) may be added as objectives of 3rd person, utuvienye-s “I have found it” (from a draft of a letter to David Masson written around 1955, PE17/110).
which seems to indicate that object suffixes only exist for the 3rd person. A safer formula would be hantan lyen with a separate dative plural.
Alternatively, one could say hantan(ye) lye, without the dative, since we simply do not know whether one should use the dative or not.