First time I saw “Butiken är stängt pga semester” written on a piece of paper and stuck on a door, I thought ‘pga’ was a typo. But it was just someone using one of the most common Swedish abbreviations (and not using dots).

Here’s the cheatsheet I wish I had back then:

pga = p.g.a. = på grund av = because of
tom = t.o.m. = till och med = up until and including (“tom Monday”)
from = fr.o.m. = från och med = from and including (“from Tuesday”)
bla = bland annat = among other stuff
dvs = det vill säga = so to say
mm = med mera = and more, etc (frequently seen in “our store sells clothes, toys, books, mm!”
osv = och så vidare = and so on
v = vecka = week (“we are closed during v26”)
ca = cirka = approximately (“it will take ca two weeks”)
tex = till exempel = for example
kl = klockan = o’clock (“can you do it kl 11?”)
ggr = gånger = times (“it is emptied 2 ggr per week”)
lgh = lägenhet = apartment (“we live in lgh 1101”)

In written communication between people where paper is not involved, these come up:
mvh = med vänliga hälsningar = kind regards (usually at the end of an email)
iaf = i alla fall = in any case, anyway
leg = legitimation = ID (like a driving license)
ngt = något = something
ngn = någon = someone
o = och = and
o (yep, again) = att = that, to (like in “to do”)
ba = bara = just, only
va = vara = be

On road signs and maps:
St = Stora = big, as in Stora Torget, name of the town square
S:t = Sankt = Saint
g:n, g = gatan = street
tgt = torget = square
järnv, jrnv = järnvägen = railway
k:a = kyrka = church

In a supermarket:
st = stycken = piece (“we sell bananas 10 bucks per st”)
cl = centiliter (no translation here, just slightly unusual units for drinks and similar)
jfr, jmfr (pris) = jämförelsepris = price for comparison (e.g. price per kg when the product is packed in cartons of different sizes)
moms = mervärdesomsättningsskatt = VAT, value-added tax