spend extra time
It is hard to say "no" to boss, so I sometimes spend extra time to do some tasks. If it's too much extra work, maybe every day, every week, I might say no..but if it does not require too much time, I usually say "yes".
JungYun,
You may want to try something like "not today" or "not right now" when you are swamped. You could also ask the boss what his or her top priority for us among the things (list them) he or she has given you to do.
Jeffrey Schillinger
