There are about twenty of us, men and boys, working here in the valley.

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Q1 What is the relationship between 'us' and men and boys'? Does 'men and boys' mean 'about twenty' or 'us'?

Q2 What does the previous sentence mean, #1 or #2?

1. There are about twenty of us, men and boys, who work here in the valley.

2. There are about twenty of us, men and boys, who are working here in the valley.

"men and boys" makes up an appositive and is detailing what is meant by "us."

This sentence and both sentences in Q2 mean the same thing.

Thank you for your help. Does the sentence mean there are about twenty workers all together? Or about twenty of how many people?

To understand the relationship between "us" and "men and boys" in the given sentence, we can break it down:

"There are about twenty of us, men and boys, working here in the valley."

In this sentence, "us" refers to a group of people, which includes both men and boys. Therefore, the phrase "men and boys" describes the composition of the group referred to as "us."

To answer Q1: The relationship is that "us" consists of both men and boys.

Regarding Q2, the sentence can be interpreted as meaning both #1 and #2 since the two versions only differ in terms of verb form:

1. "There are about twenty of us, men and boys, who work here in the valley." (Present simple tense)
This version implies that the group, which includes men and boys, has an ongoing occupation of working in the valley.

2. "There are about twenty of us, men and boys, who are working here in the valley." (Present continuous tense)
This version suggests that at the moment of speaking or referring to a specific point in time, the group, including men and boys, is engaged in working in the valley.

In conclusion, based on the original sentence, both interpretations can be valid. However, without further context, it is not possible to determine which version is intended.