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.

Ma'am

"Ma'am" is a title that people use to address a woman. It's the female equivalent of "sir".

This word is used differently in different English-speaking regions. Throughout most of the U.S., employees at banks, airports, post offices, and so on call female customers "ma'am" as a sign of respect. Students also traditionally call their female teachers "ma'am".

In the southern parts of the U.S., "ma'am" is even more common. Some men call any older woman that they don't know "ma'am".

"Ma'am" was originally short for "madam", but people don't really think about that when they use this word in modern times.

the (something) back there

You can say this to refer to an area that is somewhere behind you and the person you are speaking with, especially if both people are moving forward. 

Did you see the accident back there?

I think I knew that guy back there.

the sidewalk

A "sidewalk" is a paved area that's made for people to walk on. Sidewalks are usually next to a street.