"Nu pune degetul în gură că e plin de bacterii!"

Translation: Do not put the finger in the mouth because it is full of bacteria!

[BigWayne19]

-------- trying to make a translation into english, i'd never use the finger/the mouth . it has to be your and your . . .

Big 29 apr 19

[Christian601649]

Besides finger, toe should be a correct answer as well, right?

[Bert996208]

So many translations for because and here it just appears out of nowhere.

[ArtificialGem]

They translate că with because

[Minch25]

Maybe, by mistake, they forgot about "pentru" or it's just another way to say "because". Could someone explain it?

[_lamiina]

"Că" comes from "pentru că" It is a shorter way of saying,though not that correct, but still used.

[DavidONeil4]

Is it informal in the same way that "cause" is used in English (to make things worse, sometimes even spelled as "coz")?

[NazarioMas]

The usage of "că" to introduce causal subordinates is standard (you find it listed in dictionaries, such as DEX), unlike that of "cause" in English.
My understanding is that it is (often) perceived as somewhat less stressed than "pentru că" and more commonly found in oral speech than in written texts. There are contexts in which using "pentru că" might perhaps sound unnatural / give away that you are not a native speaker.

[DavidCarver]

which - the finger or the mouth? "Full" seems to suggest the mouth, but I guess that this is not what is intended

[NazarioMas]

The Romanian sentence uses "plin", which is masculine and, thus, unambiguously refers to "degetul". Although its most immediate English translation is "full", "plin" can also be referred to surfaces to mean that they are "completely covered with something" or figuratively to mean that "there is plenty of something" (in this context, both meanings apply).