Let us or let's/Plural form of "person"

Let us or let's

Dear Dr English

I sometimes see the phrase "let's" written in full; I wonder if they both give the same meaning. The sentences, "let's know if you need any help" and "let us know if you need any help" sound different to me; am I correct? If yes, please explain why?

Sommai Pailee

You are definitely correct in surmising that using "let's" and "let us" in this sentence changes the meaning; but it is not always the case. Even though "let us" is the full form of "let's", they are not always interchangeable.

When you want to make a suggestion that you and someone else should do something, you can use either the short or full form, except that the full form "let us" is used exclusively in formal English.

I'm too tired to cook today: let's get some fish and chips for dinner.

It's going to be a long day tomorrow: let's get some sleep.

Let us discuss the proposal at your convenience.

There are always two sides to a suggestion, whether to do something or not to do something, so to express the opposite to the above examples, we use "let's not" to suggest that you and someone else should not do something.

Rain clouds are building up everywhere: let's not go to the park.

He has not quite recovered yet: let's not disturb him.

Apart from making a suggestion, you can use "let us" to make a request on behalf of yourself and someone else, and it is in this usage that only the full form is used.

We have studied this case for a few months already, so let us do the negotiation.

It is very cold out here. Don't let us wait outside.

Plural form of "person"

Dear Dr English,

What is the plural form of "person"? Is it "people" or "persons"? Thanks.

Naowarut Piriyakit

"Person" is a countable noun, and its usual plural form is "people", but you may sometimes see "persons" as well, which is not wrong. This choice of word is used in formal English.

We saw hundreds of people gathering at the stadium.

Among the 10 persons attending the opening speech, three were from government agencies.

By Dr English

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