I. them¹ S1 W1 /ðəm; strong ðem/ pronoun [object form of ‘they’]
[Date: 1100-1200; Language: Old Norse; Origin: theim]

1. used to refer to two or more people or things that have already been mentioned or are already known about:
Has anyone seen my keys? I can’t find them anywhere.
The police were very helpful when I spoke to them.
I lent him several books, but he hasn’t read any of them.

2. used when talking about someone who may be male or female, to avoid saying ‘him or her’:
If anyone phones, tell them I’ll be back later.

[TahlilGaran] Dictionary of Contemporary English ▲

II. them² /ðem/ determiner spoken
used to mean ‘those’. Many people think this use is incorrect:
I couldn’t understand all them long words.

[TahlilGaran] Dictionary of Contemporary English ▲