casual acquaintance	person you know, but not very well
colleagues	współpracownicy (koledzy z pracy)
allies	countrues which fight on the same side (sojusznicy, sprzymierzeńcy)
partners	partnerzy (w pracy)
true friends	prawdziwi przyjaciele
to speek behind one's back	to say bad things about us when we are ot there
loyalty	support for us in good and bad times
disloyal	opposite of loyal
unsupportive, critical	opposite of supportive (x2)
dishonest	opposite of honest
untruthful	opposite of truthful
business partners	people who own the same business
bitter rivals	people in competition with each other in an aggressive and negative way
to	disloyal... (which preposition?)
of	critical... (which preposition?)
with	dishonest... (which preposition?)
scrupulously	... honest (collocation) (sumiennie)
complete and unswerving	... loyalty (collocation) (całkowita i bezgraniczna)
staunch	... ally (collocation) (~oddany)
deeply	... critical (collocation) (wnikliwie, dogłębnie)
genuine misunderstandings	"rzeczywiste" nieporozumienia
rift	serious disagreement that divides people
discord	dissagreement and discontent (rozgoryczenie)
we don't see eye to eye on most things	we have different opinions on most things
to turn sour	to become bad
to split up	to separate
to have its ups and downs	to have a good and bad moments
bumpy relationship	relationship that is up and down, like a car on a road
broken home	pamily split up by divorce
family freud	quarrel in family causing bad feelings for many years
unwelcoming	opossite of welcoming
discontented	opossite of contented (zadowolony)
cold-hearted / heartless	opossite of warm-hearted
not to see eye to eye	opossite of to share the same opinion
to turn sour	opossite of to grow stronger
to split up	opossite of to get engaged
to break down	opossite of to stay firm
to die of a broken heart	to die because of sadness resulting from eg. a love affair which te other person ended
to hate sb's guts	to dislike sb intensely (but informal)
to have it in for sb	to take advantage of every opportunity to speak badly of sb
to be on bad terms with sb	to have a bad relationship with sb