Excuse me.

Say "Excuse me" to get the attention of strangers in a polite way:

Excuse me. Do you know where the bathroom is? 

When you pronounce "excuse me", it can sound like "'Scuze me"

In some English-speaking areas, it's also polite to add "Sir" (for men) or "Ma'am" or "Miss" (for women):

Excuse me, Ma'am. You dropped this on the sidewalk back there.

But since these titles are actually thought to be impolite in some areas, it's best to listen first to see if other people around you are using them.

watch over (something)

To "watch over" something means to guard and protect it. But "watching over" something is not as serious as "guarding" it. A professional "guards" things like expensive artwork, an empty office building, and so on. But regular people can "watch over" things like someone's computer or someone's teenage child.

People often say that God "watches over" people as well:

God, we pray that you watch over Richard and his family in this difficult time.

Would you mind (doing something)?

"Would you mind ___ing?" is a good way to ask politely for something that isn't too much trouble for the other person. Some more examples:

Would you mind giving me a hand with this?

Would you mind covering for me while I'm out?

Would you mind forwarding me his reply?

In all of these examples, you're asking the other person to do something. If you want to ask for permission to do something yourself, say "Would you mind if I ___?"

A: Are you ready to go?

B: Actually, would you mind if I stay here and rest instead?

(do something) for me

Use "___ for me" when asking someone to do something that you want. It's a casual expression.

Close the blinds for me, would you?

Can you open this for me?

for just a minute

"For just a minute" means for a short length of time. It doesn't mean exactly one minute.

A: Hey, let's go.

B: Wait just a minute. I haven't brushed my teeth yet.