"Let's" is not a contraction.

M56   Sun Aug 26, 2007 7:53 am GMT
Correction:

The best way to treat "let's" is as a lexical item (as a word or fixed expression) defined by its function.
M56   Sun Aug 26, 2007 8:19 am GMT
correction:

In which situation of contemporary use would one find "let us go" or "let us not go" as a full form of "let's"?
Skippy   Sun Aug 26, 2007 4:19 pm GMT
It is, in fact, a contraction. I'm actually surprised there's so much debate about it.

It is interchangeable with "let us," though "let us" sounds a little odd... But the same is true for "I am" or "You are" or "do not."
beneficii   Sun Aug 26, 2007 10:15 pm GMT
Travis,

<<That's the thing - for very many speakers of English today, "let's go" and "let us go" do not mean the same thing at all. Rather, "let's go" is a first person plural imperative telling the group of people one is in to go, whereas "let us go" is telling someone to *allow* the group the speaker is in to go.>>

"Let us go" can also mean the same as "Let's go." It doesn't exclusively mean "a request for allowance for a group of people to go." There might have been some divergent evolution of the contraction and what it's a contraction of, but it's still a contraction. "Are not" and "Aren't," for example, don't have all the same meanings, but the latter is considered a contraction of the former.
beneficii   Sun Aug 26, 2007 10:18 pm GMT
Additionally, "Let's," for example in "Let's go," can never be properly spelled without the apostrophe. Except in, say, instant messenger where nobody cares about punctuation, I generally see the apostrophe in that phrase. There are some here, though, who seem to be suggesting that the apostrophe is not even necessary.
Pub Lunch   Sun Aug 26, 2007 11:01 pm GMT
This does seem a bit odd, let's IS a contraction of let us. From my viewpoint in England this seem quite reasonable. I have no idea what you lot abroad are doing with it??????
Guest   Mon Aug 27, 2007 5:34 am GMT
In church: "Let us pray."
Travis   Mon Aug 27, 2007 5:40 am GMT
>>Additionally, "Let's," for example in "Let's go," can never be properly spelled without the apostrophe. Except in, say, instant messenger where nobody cares about punctuation, I generally see the apostrophe in that phrase. There are some here, though, who seem to be suggesting that the apostrophe is not even necessary.<<

The apostrophe is irrelevant in that it is purely orthographic in nature and in this case seems to be largely etymological rather than actually reflecting the current status of "let's" versus "let us".
Travis   Mon Aug 27, 2007 5:59 am GMT
>>"Let us go" can also mean the same as "Let's go." It doesn't exclusively mean "a request for allowance for a group of people to go." There might have been some divergent evolution of the contraction and what it's a contraction of, but it's still a contraction. "Are not" and "Aren't," for example, don't have all the same meanings, but the latter is considered a contraction of the former.<<

I have never seen "let us go" being used to mean "let's go" except in archaic or very formal usages, and the difference between them is not simply a matter of emphasis or stress. This is unlike "are not" versus "aren't", which only differ in emphasis/stress and which are otherwise equivalent.
M56   Mon Aug 27, 2007 11:11 am GMT
<<It is interchangeable with "let us," though "let us" sounds a little odd... >>

Where is it interchangeable? Can you give real, contemporary examples of such use?
Guest   Mon Aug 27, 2007 11:13 am GMT
<"Let us go" can also mean the same as "Let's go." >

In which century?

<In church: "Let us pray." >

Yes, a fossilized form.
K. T.   Wed Aug 29, 2007 4:31 am GMT
It's a contraction.

Let us adjourn...Let's adjourn.
Rev. Bumber-Lee   Wed Aug 29, 2007 3:44 pm GMT
<<In church: "Let us pray.">>

Oh, I thought it was "Lettuce Pray". Next you'll be telling me there's no Holy Goat.
Travis   Wed Aug 29, 2007 3:50 pm GMT
>>It's a contraction.<<

Only if you count grammaticalized forms that act as independent lexical items as such.
clueless   Wed Aug 29, 2007 10:51 pm GMT
Here's what Wikipedia has to say: (My interpretation is that let's is a contraction, but a unique one. You still need the apostrophe, perhaps only as an historical artifact.)

The only commonly used English contraction of two words that does not fall into any of the above categories is "let's", a contraction of "let us" that is used in forming the imperative mood in the first-person plural (e.g. "Let's go [someplace]"). Use of the uncontracted "let us" typically carries an entirely different meaning (e.g. "Let us go [free]"). "Let us" is rarely seen in the former sense and "let's" is never seen in the latter one.