det vete fan

Etymology
Literally "That may the devil know," using the subjunctive of.

Interjection

 * 1)  (i have) no idea, who knows
 * 2)  I don't know (as an expression of being dubious about something)
 * 1)  I don't know (as an expression of being dubious about something)

Usage notes

 * The subjunctive mood is archaic to obsolete in modern Swedish, except for a few forms like and in fixed expressions. Lack of intuition among native speakers has led to the alternative forms below.
 * Sometimes appears as just . "Jag vete fan" or just "Vete fan" means "I have no idea."
 * Forms without are euphemistic.