Choosing the wrong sentence in the following sentences

Question

Here is an English grammar question from a certain English learning material I bought at the book store.

I am very confused over this.

It is said there is only one answer from the five sentences, however, I think there is no answer. All the sentences below seem grammatically fine to me.

I hope you would carefully check it out and tell me what the answer is and why, please.

Q. Choose the wrong sentence in the following sentences.

1. Deep-sea habitats are as varied as those on land.
2. Writing a novel is two times as difficult as I think.
3. He looks three times as happy as I had seen.
4. I love her as much as you.
5. Several excuses are always less convincing than one.

Thank you for reading. Take care of yourself.

Answer 1

Q. Choose the wrong sentence in the following sentences.

1. Deep-sea habitats are as varied as those on land.
2. Writing a novel is two times as difficult as I think.
3. He looks three times as happy as I had seen.
4. I love her as much as you.
5. Several excuses are always less convincing than one.

I think option #3, "He looks three times as happy as I had seen", is probably, or should be, the "wrong sentence".

For it seems to be missing the 2nd time reference point in its comparison of when he looked happy. The other four options appear to be fine.

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LONG VERSION: Here I'll go and explain a bit more why the individual options seem to be okay or not.

Option #1. Deep-sea habitats are as varied as those on land.

This appears to be fine. Two terms are being compared: "the variety of deep-sea habitats" versus "the variety of land habitats".

Option #2. Writing a novel is two times as difficult as I think.

This appears to be fine. Two terms are being compared: "the (actual) difficulty in writing a novel" versus "the difficulty that I think it takes to write a novel".

A possible context:

• If I was a young writer, I might think that I ought to be able to easily write a sci-fi novel in a year, but my parents might shake their heads in disagreement and say that that would take two years at least. And so, when I talk to a friend about this, I might say to that friend, "Writing a novel is two times as difficult as I think. That's what my parents keep telling me."

As a standalone sentence, option #2's sentence works too: the actual writing of a novel is X difficult, and I think writing a novel is Y difficult, and X is equal to 2Y.

Option #3. He looks three times as happy as I had seen.

This one seems to be malformed. And it seems to be the most awkward of all the options in the list.

Its problem seems to be that it doesn't mention within the second term (the comparative clause) a 2nd time that is being compared against. The 1st time that is being used in the comparison could be now, as in "He now looks happy", but there is no 2nd time of when he looked happy which could be used in the comparison. That is, in other words: He now (at time #1) looks X happy, and he used to (at time #2) look Y happy, and X is equal to 3Y -- but there is no mentioning of when that time #2 was.

Option #3's sentence could be tweaked into something that could work, such as "He looks three times as happy as when I had seen him last."

Option #4. I love her as much as you.

This appears to be fine, but perhaps it could be ambiguous as to how it should be interpreted, and context will probably disambiguate it. It could possibly be interpreted in two ways. One (1st) interpretation is,

1. I love her as much as you do.

where the two terms are: "I love her" vs "You love her". Another possible (2nd) interpretation is,

2. I love her as much as I love you.

where the two terms are: "I love her" vs "I love you". This 2nd interpretation of option #4 is structured similar to,

• "I love cookies as much as cupcakes."

Aside: Sometimes comparative constructions can be full of ambiguity, e.g. "She phoned Angela more often than Liz", which can be interpreted with the 2nd term being either "she phoned Liz" or as "Liz phoned her". (Example borrowed from CGEL page 1112, [20.v])

Option #5. Several excuses are always less convincing than one.

This appears to be fine. Two terms are being compared: "the convincing power of several excuses" versus "the convincing power of one excuse".

Answer 2

My guess is that sentence 3 might not be right:

3. He looks three times as happy as I had seen.

It uses the Past Perfect but there's no another past-time reference in the sentence. And probably it is wrong to end the sentence so abruptly, making no explicit comparison.

I would transform it thus:

He looked three times as happy as I had seen him look before.

Now we have a "Past Simple - Past Perfect" sentence comparing a person's past condition with his condition in an earlier past, and a more explicit comparison clause.

Note: I'm a non-native speaker, so it's only a guess. I might be wrong.

I googled in books for "as I had seen", and found a sentence with a comparable structure:

Auntie Lolo was as beautiful as I had seen her in my vision, and I remembered that..

The same sequence of tenses: Past Simple - Past Perfect.

Answer 3

2. Is incorrect - using the incorrect tense for think makes this statement internally inconsistent (ie. a contradiction). It should read:

2. Writing a novel is twice as difficult as I had thought.

3. & 4. (and arguably 5.) are not well-formed sentences semantically, but I would not go as far as to say that they are not grammatical.