To add to what Railman said, there is no such thing as a stupid question. You are entitled to clarification of everything.
Perfect example: one of the most common rules with operations that can get muddled is "expresses on the local are express unless otherwise told". if you're an A or a 4 and you're getting a local lineup, you and your partner are entitled to ask, even if they don't tell you.
"(tower/Control+ your ID information) Am I express on the local or am I making local stops for service..." Cause here's the thing... sometimes messages get stepped on, sometimes interference gets in the way. They may have given you instructions, and you didn't hear on no fault of your own. So, ask. It's better to be sure than to be explaining later.
Our communication system has it's flaws. I've had a rather rare circumstance where you had two trains going in opposite directions with the same interval time due to adjustments. I was at Queens Plaza one day, as like a 1050 Echo Parsons to World Trade and right next to me going the other way was the 1050 Echo World Trade to Parsons, and they'd only said "1050 Echo at Queens Plaza"