How to address a young or elderly lady and man

[Steven Mai]

Hi all, I barely hear a word to address a young (old) lady, like we use ma'am or sir to address an adult lady and man, but what do we say when we are trying to call a young (old) lady and man? I heard GUY and GIRL, but I find it a little informal or we only use to a familiar person. I also heard miss, is that correct?
Thank you in advance :)

[I.M. Knott]

"Ma'am" is fine for an old lady, or any adult woman. Some women, however, are rather sensitive about this usage. They feel that "ma'am" suggests an "older" woman than they perceive themselves to be.
"Miss" is technically correct for an unmarried female of any age, even for young girls. If you don't know her well, "Miss" is always a safe bet.
"Boy" refers to a male under 12. Use his first name or "young man" in addressing a boy directly. As he matures, "young man" is still appropriate for a long time. "Sir" implies some degree of respect for the man so-addressed.

[5jj]

In British English, police officers, customs officials, shop assistants and restaurant staff may use 'sir' and 'madam' when addressing adults. They generally use no form of address when addressing young people.

Most of us do not use any form of address when speaking to people whose name we don't know. We simply have no BrE equivalent yo the French 'monsieur/madame', the Spanish 'señor/señora', etc

[Raymott]

The same applies in Australia as what 5jj said. We simply don't have terms for addressing young people we don't know.

[I.M. Knott]

A lot of young Americans seem to be using "dude," "bro," "man" and similar terms in addressing their peers. Do Australians say "mate,"
or is that just a stereotype?

[probus]

I was a bit distressed when people began addressing me as "sir". I felt they were using the word very prematurely. ;)

[JMurray]

not a teacher

A lot of young Americans seem to be using "dude," "bro," "man" and similar terms in addressing their peers. Do Australians say "mate," or is that just a stereotype?

"Mate" remains very common in Aust/NZ and "man" has been quite common for some time. I do hear "dude" and "bro" increasingly, "bro" being particularly associated with Maori English although its use is much wider.

[MikeNewYork]

Hi all, I barely hear a word to address a young (old) lady, like we use ma'am or sir to address an adult lady and man, but what do we say when we are trying to call a young (old) lady and man? I heard GUY and GIRL, but I find it a little informal or we only use to a familiar person. I also heard miss, is that correct?
Thank you in advance :)

"Sir" and "Ma'am" work well for adults (older adults in the case of females). "Miss" can work well for younger adult females and younger. "Lad" can work for younger males. "Young man" and "Young woman" can also be used for younger males and females.

[5jj]

"Lad" can work for younger males. "Young man" and "Young woman" can also be used for younger males and females.

I recommend that you do not use any of these when speaking to British young men. They can sound old-fashioned and/or condescending.

[MikeNewYork]

I recommend that you do not use any of these when speaking to British young men. They can sound old-fashioned and/or condescending.

They are fine in the US.