I can't swear to have/having? heard him correctly.

[sitifan]

I think that is what he said, but I can't swear to have heard him correctly.
(my bold, Ho's Complete English Grammar, Book 5, page 63)
Is the above sentence grammatically correct?

 

[emsr2d2]

No. It should be "having".

 

[teechar]

I think that is what he said, but I can't swear to have I heard him correctly.

That is also possible.

Ho's Complete English Grammar, Book 5, page 63)

I couldn't find that on Google. Can you cite it properly, or give us a link?

Is the above sentence grammatically correct?

No. See above.

 

[Tarheel]

Perhaps:

I think that's what he said.

Or:

I think that's what he said, but I'm not certain.

Or:

I think that's what he said, but I'm not sure.

Or:

I think that's what he said, but I can't swear to it.

You really don't need anything more than the first sentence.

 

[sitifan]

I couldn't find that on Google. Can you cite it properly, or give us a link?

Copyright © 1998-2012 Ho's Complete English Grammar All Rights Reserved
http://www.hosenglish.com/

Complete the sentences, using a suitable verb form.​

257. I think that is what he said, but I can't swear to (have) heard him correctly. (Ho's Complete English Grammar, Book 5, page 63)
Answer Key: 257. have.
(Ho's Complete English Grammar, Book 6, page 85)

 

[Tarheel]

I would almost always use the contraction. Also, when you say "I think" you have already said you're not sure.

 

[jutfrank]

I can't decide whether I think it's ungrammatical or not. It's certainly okay to use a to-infinitive after 'swear', but there's something about the sentence that sounds wrong. Is it possible this is an old-fashioned usage?

Normally, the pattern 'swear to do something' has a future meaning, loosely similar to 'promise'. It doesn't seem to make sense to be about the past.

 

[emsr2d2]

I can't decide whether I think it's ungrammatical or not. It's certainly okay to use a to-infinitive after 'swear', but there's something about the sentence that sounds wrong. Is it possible this is an old-fashioned usage?

Normally, the pattern 'swear to do something' has a future meaning, loosely similar to 'promise'. It doesn't seem to make sense to be about the past.

"Swear to do something", though, has nothing to do with the current context. I have absolutely no issue with "I can't swear + past context" when expressing uncertainty about something that happened.

I think he said "Yes". I can't swear I heard him correctly though.
She thinks she bought a cabbage in the supermarket. She can't swear she did, though. She'll have to check when she gets home.
I'm pretty sure I've seen that film but I can't swear to it.

 

[jutfrank]

I think he said "Yes". I can't swear I heard him correctly though.

Yes, that's what it seems to mean.