How many taxi driver in shanghai can read an adress in Pinyin?

I listen the word "visited" with the meaning of "small talk". Is this common?

What is the difference meaning between effect and affect?

on leave, on vacation, on holiday In the last time did I listen more frequently "on leave" instead "on vacation". Is there any different meaning or use in different situation from "on leave" "on vacation" "on holiday"? Or is the selection of one of this words, just depends on the location? And if yes where do they use which one?

Why isn't the "b" from "doubt" pronounce? Is there any rule for this kind of pronouncation?

consultant - temporary worker - contract worker Whats the best description for a employe which one company hire from an other company to extend the staff for a better capacity balancing. In Germany do we use in the development department usually the word Consulter which looks similare to consultant, but I think the meaning doesn't fit. Because these engineers does the same work as the core staff. Contract worker, doesn't fit because they doesn't do hire for a specific task. They are integrated in the normal business process. Temporary worker sounds quite unusual. How do you call such kind of rented white collar worker?

What described me best when I cover the functions from colleagues or the boss during there absence? This should be in a normal office situation and I'm in general nominated to cover the function of a specific colleague or the boss additional to my normal work. I found different possibilities but I never listen any from this possibilities in the real life: I'm the proxy from ... I'm the deputy from ... I'm the substitute from ... I'm the replacement from ... How would you describe someone in this function resp. this situation?

"copy" used as acknowledge ? I listend frequently in movies something like "copy" when someone acknowledge a message by phone. Does they really the word "copy"? Why does they use the word copy? (I thought this have somethink to do with replications)

It's right to use "an" in "I'm an manufacturing engineer" ? I think that when the "an" is related to the engineer it's right. But maybe it doesn't matter and it has to be a simple "a" because it's in front of the "manufacturing"