Use and misuse of 误认为

[anonymoose]

误认 according to nciku.com means "to take something for, hold the misconception that". I think, in order to introduce what the subject was mistaken for, this phrase should be followed by 为 and then a noun phrase indicating what it was mistaken for, as in for example: 操作系统中几个容易被误认为病毒的文件. Here, 为 could be explained as meaning 是.

However, there seem to be many examples where 为 is followed by 是, as in: 肝癌早期症状有时会被误认为是日常疾病. Is this because in this situation, 误 modifies the verb 认为, and then 是 introduces what the subject was mistakenly thought to be, or is the 是 superfluous in these examples?

[creamyhorror]

Is this because in this situation, 误 modifies the verb 认为, and then 是 introduces what the subject was mistakenly thought to be

Yeah, I'd think so. Either construction (with or without 是) should be valid.

[chinchillus]

1.这个文件被误认为带病毒的 = 这个文件被误认为是带病毒的

2.我把这个文件误认为带病毒的 = 我把这个文件误认为是带病毒的

3.我误认为这个文件是带病毒的 ≠ 我误认为是这个文件是带病毒的(X)

4.我误认贼人为父 ≠ 我误认贼人为是父(X)

In 1) and 2), 认为 is "to regard as". Here 是 refers to "as". 是 can be used or omitted.

In 3), the latter is a wrong sentence. 认为 is "to think that...". 是 should not be used.

In 4), the latter is a wrong sentence. 认 and 为 are split. 认+甲+为+乙, to consider A as B. 是 should not be used.