I'd allow that "a couple of things" could mean 3, even 4 at a stretch - you're downplaying the size of the task to make it sound like your request isn't unreaso

I'd allow that "a couple of things" could mean 3, even 4 at a stretch - you're downplaying the size of the task to make it sound like your request isn't unreasonable. But a couple of some specific item (can of coke, etc.) means 2 - if they brought back 3 I'd ask them what's the 3rd one for.