"Vi vasker klærne."
Translation:We are washing the clothes.
Is klær irregular and makes klærne when I want to say the clothes? Or is this some other rule to this? And is his/her clothes correct translation of klærne? If so, why is that?
Somewhat irregular yes. 'klærne' = 'the clothes'
'his/her clothes' isn't a correct translation of 'klærne', but could be a possible translation given the right context. 'his/her clothes' would most likely translate to 'klærne hans/hennes'.