General Question about "...than.."

[Hei]

X is/was/are/were .... than Y is/was/are/were.
However, sometimes, I find that the "is/was/are/were" behind "Y" is omitted. I just wonder when I can omit it and when I cannot.
Similarly,
- X [some action verb] ... than Y do/does/did
- X has B more than Y has/have
When can I omit the verb after "Y"? When cannot?

Another one is the placement of the verb in the "...than..." form sentence, I saw some SC questions like:
- X [some action verb] than do/does/did Y.
How come the verb, "do/does/did" is placed in front of Y?

Thanks in advance.

[RonPurewal]

This is another example of a principle that is difficult/obscure because it sounds terrible to our ears, but is widely respected in writing.

In general, you can think about the actual comparison that's being made. If it's the two actual items - or their intrinsic qualities - that are being compared, you can omit the helping verb. For instance, you can say 'Laura is prettier than her sister', because you're actually comparing Laura and her sister. On the other hand, you must say 'Laura spends more time studying than her sister does' or '..than does her sister', because you're not comparing the sisters but, rather, their study habits.

'Than does X' is mostly a stylistic device that emphasizes X (by placing it last in the sentence - we all know that placement at the end of a sentence, or a grocery list for that matter, makes something 'seem more important', whether it really is or not). You don't generally hear it in spoken English, but it is de rigueur in formal written English. (You will not often see good writers WRITING '...than her sister does', although you will certainly hear those writers SAYING it around the water cooler.)

Incidentally, helping verbs that are unnecessary in shorter sentences usually do appear in longer sentences, if for no other reason than to help string the pieces of the sentence together more logically and easily. For instance:
* Ahti is more likely to succeed than most other students at the university. (short sentence) Notice that you CAN use 'are' here, but that it's by no means necessary.
* Ahti is more likely to succeed in business, using his charisma and tenacity to build a successful firm, than are most other students at the university. (long sentence - notice how much harder it is to read if you remove the 'are').

[Hei]

Much clear now.
Thanks Ron.

[Nov1907]

Thanks for the explanation Ron and for bringing up the question Hei! I had a similar issue understanding when to add the verb and when to leave it out. An addendum to the question Ron. You say "than does her sister" is acceptable as well. Is it acceptable to separate the verb from the object like that?

[StaceyKoprince]

With "than her sister does" or "than does her sister" - we're not technically separating the verb from the object here. It's just a question of which comes first and which comes second. Either order is fine and, as Ron notes, it is more common in formal written English to see the "than does her sister" option.

[kiranck007]

This is another example of a principle that is difficult/obscure because it sounds terrible to our ears, but is widely respected in writing.

In general, you can think about the actual comparison that's being made. If it's the two actual items - or their intrinsic qualities - that are being compared, you can omit the helping verb. For instance, you can say 'Laura is prettier than her sister', because you're actually comparing Laura and her sister. On the other hand, you must say 'Laura spends more time studying than her sister does' or '..than does her sister', because you're not comparing the sisters but, rather, their study habits.

'Than does X' is mostly a stylistic device that emphasizes X (by placing it last in the sentence - we all know that placement at the end of a sentence, or a grocery list for that matter, makes something 'seem more important', whether it really is or not). You don't generally hear it in spoken English, but it is de rigueur in formal written English. (You will not often see good writers WRITING '...than her sister does', although you will certainly hear those writers SAYING it around the water cooler.)

Incidentally, helping verbs that are unnecessary in shorter sentences usually do appear in longer sentences, if for no other reason than to help string the pieces of the sentence together more logically and easily. For instance:
* Ahti is more likely to succeed than most other students at the university. (short sentence) Notice that you CAN use 'are' here, but that it's by no means necessary.
* Ahti is more likely to succeed in business, using his charisma and tenacity to build a successful firm, than are most other students at the university. (long sentence - notice how much harder it is to read if you remove the 'are').

Hi, Ron.

A query. is "are" parallel " to "is" or "succeed" ?
Here is what I understood as the intended meaning of the sentence,
Ahti is more likely to succeed in business, using his charisma and tenacity to build a successful firm, than most other students at the university are likely to succeed in business.
In the above expanded sentence, What is being substituted by "are", so as to arrive at your sentence.
What I am coming to is condensed version should be arrived at by using a rule so that we can go back to the original intended meaning. I hope I have put across my thoughts well.

Thanks

[jlucero]

Hi, Ron.

A query. is "are" parallel " to "is" or "succeed" ?
Here is what I understood as the intended meaning of the sentence,
Ahti is more likely to succeed in business, using his charisma and tenacity to build a successful firm, than most other students at the university are likely to succeed in business.
In the above expanded sentence, What is being substituted by "are", so as to arrive at your sentence.
What I am coming to is condensed version should be arrived at by using a rule so that we can go back to the original intended meaning. I hope I have put across my thoughts well.

Thanks

Yes, Ahti is more likely to succeed than other students are likely to succeed, is the correct meaning of the sentence, so "is" is parallel with "are".