Tom is less tall than Jack. vs Tom is shorter than Jack.

[diamondcutter]

1. Tom is less tall than Jack.
2. Tom is shorter than Jack.
(By me)

The first sentence indicates both Tom and Jack are tall but Tom is not as tall as Jack.
The second sentence doesn’t tell us whether Tom and Jack are both tall or short or else. It just tells Tom is not as tall as Jack.


Is my understanding correct?

 

[tedmc]

1 is not correct. It should be "Tom is not as tall as Jack".
It is just a comparison; it does not mean they are tall.

2 would be the same as 1, after my correction above.

 

[diamondcutter]

I found these sentence in dictionaries.

I often think about those less fortunate than me.
https://www.collinsdictionary.com/dictionary/english/less

Tickets were less expensive than I had expected.
https://www.ldoceonline.com/dictionary/less

If these sentences make sense, I want to know why my first sentence in the OP doesn’t.

 

[jutfrank]

Is my understanding correct?

Not really. You're right about sentence 2, but with sentence 1, your interpretation that they are both tall is only one possible meaning. It's also possible that they are both short, or medium-height, since 'tallness' can be understood as a synonym for 'height'. When we ask somebody How tall are you?, we just want to know their height—we're not asking anything about how their height relates to other people. It's the same deal with other question words, like how long, how big, etc.

 

[diamondcutter]

Thanks, jutfrank.

From your reply, I can infer that both my sentences in the OP are correct. Now could you please tell me if there’s any difference between them?

 

[jutfrank]

Yes, they're correct grammatically. What kind of difference do you mean? Meaning? We've already mentioned that. Be more specific about what you want to know.

 

[probus]

We don't use less tall for the same reason we don't normally use less old. We have two perfectly good and very natural words: shorter and younger.

 

[GoesStation]

We don't usually use more and less with adjectives that have comparative forms or when a comparative exists that's a synonym of the phrase. Less tall = shorter.