Quite a lot of technology is "kind of obvious." A saw is a saw and a hammer is a hammer, no matter what is stamped on the tool. There are a few details, like stainless steel vs. ordinary steel, but that mostly matters for experts in a few applications.
Other technology is based on defaults which are ingrained habit to us, and would be a problem for people. Cars have the clutch, gas, and brake pedals in a certain order, and a driver who has to think about that would have lots of accidents. An expert in the area should be able to figure things out if he is given some time and material for experimentation, but the society in general would suffer.
Yet other technology is completely dependent on written information. You cannot tell a 200-mg ibuprofen pill from a 600-mg pill by taste or look. Problems from things like that would be quite devastating until almost everyone knows the new language. Quite a lot of casualties for many months.
But I would expect that the language barrier would be broken really fast, there is just so much written stuff that with helpful pictures in it. A scientist who gets something like the Handbook of Mathematical Functions would not just deciper our number system (that could be done with a phone book) but also get a Rosetta Stone to the rest of the language.
The problem: could the scientists do the work while society breaks down around them?
And then there are things which are deliberately password-protected. With all password owners gone, who will figure out a smartphone?