Nguo is in the 9/10 (N) class. Nouns and djectives in the 9/10 class do not indicate plural or singular and the form of "new" is mpya in both cases.
Nyumba mpya imejengwa.
= A/the new house has been built.
Nyumba mpya zimejengwa.
= (The) new houses have been built.
Mipya is only used with class 4 nouns (plural of the M-MI class), which also begin with Mi-
Mito hii ni mipya.
= These pillows (or rivers) are new.
-pya has the following forms for all the noun classes.
- mtu mpya = new person
watu wapya = new people
mto mpya = new pillow/river
mito mipya = new pillows/rivers
dirisha jipya = new window
madirisha mapya = new windows
kitanda kipya = new bed
vitanda vipya = new beds
nguo mpya = new cloth/garment
nguo mpya = new cloths/clothes/garments
ukuta mpya = new wall
(10. kuta mpya = new walls)
ugonjwa mpya = new illness
(6. magonjwa mapya = new illnesses)
15. kula kupya = new eating (!? ... I suppose if you want to say something like "drinking is the new eating", maybe?)
16. mahali papya = in a new place
17. nyumbani kupya = at a new house
18. nyumbani mupya = in a new house