Less vs least
Well, I always had problems between those two and I would like to know when to use which one...
"This way is the less long to go"
"This way is the least long to go" (this one I guess is the correct, but I always doubt)
What is more correct, why and in which cases I should use each one?
.
Thanks in advance, both replies on english or spanish are accepted ^^
15 Answers
If you use the definite article "the" with the word "least" then you are stating that there exists no other thing of this class (in this case, you are referring to the way/route) that is lower in value (in this case the value is in reference to the distance).
This is a long-winded way of saying that "the least" acts as a superlative.
If you use "less" then you are generally using it as a comparative to demonstrate the relationship between two or more values.
For example, you might say:
• This route will take the least (amount of) time (of every available route)
• This route will take less time to travel (than the other/than some of the others/than all the others)
but you wouldn't say, "This route will take the less time..."
Less is used when comparing two things and no more.
Least is used when comparing three or more things.
This topic intrigued me, so, I did some research 
This is what I came up with:
Less and least are the comparative and superlative forms of little.
Positive = Little
Comparative = Less
Superlative = Least
The degrees of comparison are known as the positive, the comparative, and the superlative. (Actually, only the comparative and superlative show degrees.) We use the comparative for comparing two things and the superlative for comparing three or more things.
Random Tip: Notice that the word than frequently accompanies the comparative and the word the precedes the superlative.
Little is an irregular adjective, thus, it doesn't have the "traditional" endings such as big, bigger, biggest etc.
Does this prove/clarify my point any further?
Least means what you are referring to is smallest of all. Less means something is smaller than the other thing you are comparing it to.
Trying to use your sentences as examples, long might be an awkward word here. This way is less far to go. (than the other way you are considering) This way is least far (of the implied multiple alternatives you are considering)
I do not have detailed grammatical rational to accompany my reasoning, only that I did not have to take English in college because I understood the language.Native Speaker
Out of my manager and I, I have the least amount of experience here least is being used to compare two elements and not "more than two elements."
Oh boy! I, simply, would never say this (unless hot irons were being held to my feet and my release were conditional on my saying it).
Firstly, a simple mechanical error, the first "I" should be "me" (both it and "manager" are governed by the preposition "of". Secondly (as a matter of style more than grammar), I would either eliminate the "out" or replace "out of" by "between". Finally, I would say "I have the lesser (amount of) experience" (or, more often, "I am the less experienced"). This last puts me squarely in the camp of comparative --> for two & superlative --> for 3/more. While I understand your use of "least" in this context, I don't use it that way, myself. (I also shudder at the thought of putting whipped cream on top of a slice of pie.)
The general topic/issue is often referred to (in grammatical circles) as "superlative of two" (plenty of hits in Google for the phrase). Apparently it began to be a topic for debate among grammarians some time in the 18th century. At any rate, you can find plenty of support for your position (though, by no means, universal support).
I found an interesting account of the "superlative of two" (Thanks Samdie) in Webster's Dictionary of English Usage (881, 882):
Two things should be noted about this rule. First, it makes no difference from the standpoint of communication whether you use the comparative or the superlative of the two. No one will ever misunderstand you if you say "She is the older of the two" or if you say "She is the oldest of the two." The rule serves no useful purpose at all. It is therefore a perfect shibboleth, serving no practical function except to separate those who observe the rule from those who do not. [This pinpoints my own problems with this "rule"]
The second thing is that the rule clearly has never reflected actual usage. It is plain that many of our best writers have used either the comparative or superlative of the two, as suited their fancy at the time. Among the writers who found the superlative appropriate for two are: Shakespeare, Milton, Defoe, Addison, Goldsmith, Dr. Johnson, Chesterfield, Austen, Byron, Scott, Irving, Hawthorne, Thackeray, Disraeli, Ruskin, Emerson, Stevenson, Thoreau and James Russell Lowell.
While I don't claim to be anywhere even remotely as adept at the English language as the giants on this list, it is at least comforting to know that my own opinion regarding this subject appears to coincide with the de facto opinions of these great writers.
Here are some additional examples that I hope will demonstrated the difference in usage between the two.
• You could at least listen when I talk to you (correct)
• You could at less listen when I talk to you (incorrect)
• The road you chose took less time to travel (correct)
• The road you chose took least time to travel (incorrect)
• The road you chose took the least time to travel (correct)
• The road you chose took the less time to travel (incorrect)
• The time it took was the least of our problems (correct)
• The time it took was the less of our problems (incorrect)
Now I would like to give one final example to show that there are times where a phrase can be similarly constructed, yet each will convey a slightly different meaning:
1). I was least concerned with time that it took
2) I was less concerned with the time that it took
Each of these phrases is correctly constructed; however, the first is saying that out of all the things considered, the time was the lowest priority
Pienso que quiere decir «lo menor»
The second phrase; however, cannot really stand by itself and requires an additional phrase to compare what the speaker was less concerned about.
• I was less concerned with the time that it took than with the amount we spent on gas.
• Preocupé menos por el tiempo que por el dinero que tenemos que pagar por la gasolina
Less is used when comparing two things and no more.
Least is used when comparing three or more things.
I would say that this assertion is at best ambiguous and at worst incorrect.
Both of the following two sentences make a comparison between the speaker´s financial state to that of an entire group which in both cases could be considered as a single entity (i.e. the group as a whole) or individually (i.e. in comparison to each member of said group)
Out of all of my friends, I have the least amount of money
I have less money than all my friends
It is your second sentence that give me problems. What this actually means, is that my money is less than the combined resources of all of my friends. If you really want to preserve the use of "less" (as opposed to using "least"), I would suggest "I have less money than any/each (I prefer the former) of my friends." Alternatively, Out of all of my friends, I have the least amount of money
I have read and reread your response, and I can't quite come to agree with the accuracy of this analysis. On one hand, I do see your point that the use of "each/any" or any other similar formulation results in a less ambiguous sentence; however, I disagree with the contention that it is not possible to take the word "all" in the sense that it refer to the money held by each friend individually rather than as the sum total held by the group.
By definition (Webster's New World), the word "all" may refer to "the whole extent," "the entire number of," "any" or "every one of." It is these last two usages that make it problematic for me to accept your assertion that the sentence may only refer to the sum total of the money and that by no means may it refer to the individual amounts possessed by each friend individually.
However, as I said before, the use of the word each (while certainly not more "correct") is certainly more precise and, therefore, less ambiguous.
Despite this, I still believe your argument to be a bit specious if your contention is that it is not possible for the word "all" to be used to refer to "every one" and can only refer to a sum total of elements. This contention does not appear to hold up in situations where the element being referred to is not an item that is normally given to combined measurements. For example:
• My friends are going bald, but unfortunately, I still have less hair than all/each/any of them.
• I have less hair than all/each/any/every one of my friends, and the worst thing about it is that I just started going bald this month
While I agree that the word each is definitely more precise, I find little if any ambiguity in the sentence as it would be read using the word "all." As hair is usually not a commodity that is given to summation (as money is), it would likely be necessary to include some qualifying phrase to "force" the word "all" to refer to the sum total of hair possessed by the speaker's friends. For example:
• I have less hair than all my friends (individually - qualifier is unnecessary)
• I have less hair than all my friends combined (qualifier is necessary to indicate the sum total of hair)
I disagree that these illustrate the point that you are trying to make (and I suspect that I disagree with the point, as well).
I would be interested to read your argument against this. My initial point was that I don't believe it valid to argue that the word "less" may not be used in comparisons involving more than two elements and conversely I challenge the validity of claiming that "least" may only be used in comparisons involving more than two elements.
For example
• All of the new hires at my job have less experience than I do. In this instance the comparison can be between any number of elements as the number of new hires can be any integer value equal or greater than one. This appears to refute the idea that a comparison using less may only involve two elements and no more.
• Out of my manager and I, I have the least amount of experience here least is being used to compare two elements and not "more than two elements."
We use the comparative for comparing two things and the superlative for comparing three or more things.
Does this prove/clarify my point any further?
Yes, I am familiar with this assertion, and no it does not clarify your point. What I am getting at is that this seems an artificial distinction and somewhat flawed in its application - possibly even contradictory.
If I say
"I have the least amount of experience where I work."
There are two ways to divide the groups being discussed. In both instances the first element (E1) will be the element to which the superlative/comparative refers, so we will only be concerned with the other element(s) to which it is being compared.
1). The first way to consider the remaining elements is to group them so that they can be considered as a single entity. If defined this way, then the comparison is simply one between E1 and the group of remaining elements being compared. This distinction leads to a comparison that involves only two elements: E1 and the remaining elements, considered as a single entity/element.
2). The other way to consider the remaining elements would be to consider each element individually. If this is the case then each remaining element (En) contributes to the total number of elements being compared. So in a group comprised of 4 elements, E1 will be compared to a total of 3 additional elements (E2, E3 and E4).
Now taking this into consideration, let's apply this to an actual situation.
Superlative
I have the least amount of experience at my job
Comparative
I have less experience than the rest of my coworkers
Now let's examine these two similar sentences. Defining the group according to the rules set forth by the first case (1), the remaining elements will be taken as a single entity so that there will only be two elements in each comparison. However, this would make the original statement regarding the superlative false, so if we are to apply these rules evenly, then it is not possible to regard the second element as a single entity.
That leads us to the second case (2); whereby, each remaining element is regarded as a separate entity. Now consider the effect of defining the set as composed of 3 elements E1, E2 and E3. This would mean that the comparison would consist of 3 elements - the superlative/comparative (E1), E2 and E3. If this is the case then the original statement regarding the comparative would be considered false.
To make the definitions presented above valid requires that you define the groups by different rules according to whether you are using the comparative or the superlative, respectively. Again, as I said, this appears to be an artificial distinction which serves little purpose other than to confound the language.
To present the argument another way, if I were to say that a process required two components, "X" and "Y," and that Y was less important than X to make the process work then this means, because there are only two elements in the process that neither of the components can be considered the least important; that is, neither component can be considered to be at the very bottom of the order. In fact, in this scenario (by the given definition) it would not even be possible to make utter a statement such "Y is the least important" because by your criteria above, "Neither, is the least important" yet out of two elements in a set of two, "one of the elements in the set is less than the other." I just can wrap my brain around this distinction. How is it possible to have a set of two elements, and one of the elements is less important than the other, yet in the same breath, neither of the two elements is the least important?
How do you reconcile this disparity?
I wouldn't recommend that you use either of the two words in this way
Generally, you want to avoid circumlocutions such as these. It would be better to recognize that least long/less long would be better said as "shortest." For example:
This way is the shortest route
Out of all of my friends, I have the least amount of money I have less money than all my friends
I disagree that these illustrate the point that you are trying to make (and I suspect that I disagree with the point, as well).
The first sentence seems pretty straightforward. If the amount of my money and those of each of my friends are arranged in ascending sequence (using the mathematical concept of ">="), then my amount would come first (or in the extreme case be tied for first).
It is your second sentence that give me problems. What this actually means, is that my money is less than the combined resources of all of my friends. If you really want to preserve the use of "less" (as opposed to using "least"), I would suggest "I have less money than any/each (I prefer the former) of my friends." Alternatively, Out of all of my friends, I have the least amount of money
Wow, I have to say that I didn't know this subject about less and least was so controversial xD
Thanks to everyone for the replies and very very nice explanations about it. I think by now you can all understand why I had problems with this two little words. Thanks again for the hard work explaining
Both of the following two sentences make a comparison between the speaker´s financial state to that of an entire group which in both cases could be considered as a single entity (i.e. the group as a whole) or individually (i.e. in comparison to each member of said group)
Out of all of my friends, I have the least amount of money
I have less money than all my friends
.......Ok, I stand corrected. 
Ok clear enough, that last one got me to understand it.
The opposite between less/least and more/most was very helpful also.
Thanks to both!
