[Grammar] Know somebody to be/do something

[nininaz]

Hello all,
Is the bold context follow the italic blue pattern below?, as I don't know if preposition 'to' belong to verb 'trust' or 'know'.

have information 1[transitive, intransitive] to have information in your mind as a result of experience or because you have learned or been told it
[FONT=&quot]know somebody/something to be/do something[/FONT] We know her to be honest.

http://www.oxfordlearnersdictionaries.com/definition/english/know_1?q=know


"The managers did not know whom to trust."

 

[jutfrank]

No, that's a different pattern. The verb know is often followed by a wh- infinitive clause.

I don't know what to say.
Do you know where to go?
She knew exactly what to do.

In all examples, in both patterns, to is part of a to-infinitive verb.

 

[nininaz]

No, that's a different pattern. The verb know is often followed by a wh- infinitive clause.

I don't know what to say.
Do you know where to go?
She knew exactly what to do.

In all examples, in both patterns, to is part of a to-infinitive verb.

Could you please tell me why we use 'whom' ? If that pattern is not correct , how do we know to put 'who' or 'whom'?

 

[Matthew Wai]

Could you please tell me why we use 'whom' ?

jutfrank already told you why below.

The verb know is often followed by a wh- infinitive clause.

 

[nininaz]

jutfrank already told you why below.

You should read the rest of my sentence as well !!

"If that pattern is not correct , how do we know to put 'who' or 'whom'?"

I have no problem using 'WH' word, otherwise I want to know why we use 'whom' instead of 'who' .

 

[Matthew Wai]

Because 'whom' is the object of 'to trust'.

 

[nininaz]

Because 'whom' is the object of 'to trust'.

it is like:
I don't know whom to meet tonight. (object - meet somebody)
I don't knew who to answer the question.(subject - somebody answer the question)

 

[Matthew Wai]

I would say 'I don't know who will/should answer the question'.

The following might be worth your reference.
https://en.oxforddictionaries.com/usage/who-or-whom

 

[nininaz]

The pattern with the infinitive works only if the subject is the same in both parts.

Lots of thanks teacher. such a great tip.:up: I didn't know about it before.