There are many words that sound very similar in English and Spanish—admitir and admit, guitarra and guitar—and this is obviously quite handy for me and makes sense since despite being Germanic English has its fair share of words from Latin. Still, it is dangerous to make assumptions about these things as “embarazada” does not mean embarrased, but pregnant.
An area where one might anticipate less confusion would be among Spanish speakers themselves, but such is not the case. Much like a British person asking for a “torch” but wanting a flashlight not a flaming stick, some things just don’t correlate across continents. The textbook we use in my class is from Mexico and often our teacher will have to point out words that are not used here or actually mean something else entirely. For example, the way one in Mexico would say, “I am going swimming in the pool” in Colombia would mean, “I am going swimming in the watertank.” Sounds significantly less enjoyable. The word for brunette hair in Spain is only applied to dark skin in Colombia. Both words for sink in Mexico don’t mean anything here!
I think one of my favorite examples of this so far relates back to an earlier discussion on coffee. In class the other day we were doing a worksheet that used Cuban Spanish and it mentioned a girl who liked “cafecito con leche” or coffe with milk. If she wanted it with no milk she would have said “café negro,” black coffee. In Colombia you just say “café” and it is assumed you want coffee with milk, since black coffee has its own word: “tinto.” However if you go to Spain and say that they will think you want red wine, “vino tinto” and instead you have to ask for “perico.” Be careful if you come back to Colombia though, “perico” is cocaine. And while that will certainly get you going in the morning, it is a bit more frowned upon as an addiction.