Hello Huang,
The answer is simple. You would be better using 'her', not 'she', in all
your examples.
However 'she' is allowed where referring to subject with verb 'to be'. Thus
you can say either 'It is her' or 'it is she'. The former is much more
common, but "it's her" is most common. Similarly you can say 'It is me' or
'It is I'. The latter sounds rather biblical - i.e. it is what was used in
the bible. And you can say 'it is him' or 'it is he'. The latter now
sounds bizarre to my ear, though technically correct; and your example -
"that's he" - just sounds totally wrong to me. But "that's she" sounds
equally wrong.
BTW, we still stick to subject form in, for example: "He, she and I went
fishing", or even in "It was he, she and I who went fishing".
Cheers from Chiswick,
John
>I got confused with the usage of subject form and object form of
> pronouns.
[quoted text clipped - 28 lines]
>
> Huang
Huang, Jianshi - 30 Dec 2004 04:44 GMT
Thank you, John.
I think I should throw away that hidebound grammar book.
Best Regards,
Huang
> [snip]
>
> 3) After reading the following sentences in a grammar book. I got
> confused and frustrated thoroughly.
Whether we use a subject pronoun or an object pronoun in a sentence
depends on the function of the pronoun within the sentence.
1. We use a subject pronoun when the pronoun is the subject of a verb
or when the pronoun refers to the subject or completes the meaning of
the subject.
2. We use an object pronoun when the pronoun is the direct object of a
verb, the indirect object of a verb, or the object of a preposition.
We also use an object pronoun when the pronoun refers to the direct
object or completes the meaning of the direct object.
> I thought it was she.
The above sentence is correct. The subject pronoun "she" completes
the meaning of the subject "it"; the subject pronoun "she" is used
with the verb "was", the past form of the linking verb "be". The
noun clause "it was she" is the direct object of the verb "thought".
> I thought it to be
> her.
The above sentence is correct. The expression "to be her" completes
the meaning of the direct object "it"; the object pronoun "her" is
used with the infinitive "to be".
> I was taken to be she.
The above sentence is correct. The expression "to be she" completes
the meaning of the subject "I"; the subject pronoun "she" is used
with the infinitive "to be".
> They took me to be her.
The above sentence is correct. The expression "to be her" completes
the meaning of the direct object "me"; the object pronoun "her" is
used with the infinitive "to be".

Signature
Mary Ng
einde. ocallaghan - 31 Dec 2004 03:29 GMT
>>[snip]
>>
[quoted text clipped - 12 lines]
> We also use an object pronoun when the pronoun refers to the direct
> object or completes the meaning of the direct object.
I'm afraid natural idiomatic English doesn't follow these rules, e.g.
"Who's there?" - "It's me".
>> I thought it was she.
>
> The above sentence is correct.
However, it sounds very old-fashioned. "I thought it was her" is the
usual form.
<snip>
>> I was taken to be she.
>
> The above sentence is correct.
I have never ever heard this form being used. It sounds terribly
unnatural and forced to me. More idiomatic would be "People thought I
was her." - or "People mistook me for her."
Regards, Einde O'Callaghan
Mary Ng - 04 Jan 2005 06:19 GMT
>>>[snip]
>>>
[quoted text clipped - 34 lines]
>
> Regards, Einde O'Callaghan
I was commenting on the correctness of the sentences. The ones using
the subject form may sound old-fashioned and unnatural, but they are
correct and used in formal writing; the object form is used in
informal contexts.

Signature
Mary Ng
einde. ocallaghan - 04 Jan 2005 22:14 GMT
>>>>[snip]
>>>>
[quoted text clipped - 39 lines]
> correct and used in formal writing; the object form is used in
> informal contexts.
Not quite. The object form is often used today in quite formal
situations. Use of the subject form often sounds comically pedantic - to
my ear it rarely sounds natural.
Regards, Einde O'Callaghan
(native speaker and experienced teacher of English)