昨天你给谁打电话了?其中宾语用whom还是who whom did you called yesterday?Whom did you talk to at the information desk at the airport?

当然是whom，狭隘上就是作宾语就用whom，广义上who可以代替whom了，如果同时出现这两个选项，且是宾语，就选whom,.楼主真用功哈，三点就起床了。呵呵，祝你成功!

是Whom did you talk to at the information desk at the airport?
因为talk to的后面要加宾语，要用宾格形式-whom。
举个例子：是talk to him而不是talk to he，所以疑问句是一个道理。

Whom 是符合正规语法的表达,但是现在英语的趋势是whom可以被who代替,不算错.
你如果是在做语法题,建议还是用whom.
如果你只是自己有兴趣问这个问题,我告诉你都可以.
下面是维 基百科在“who”的页面对于这倾向的分析,有兴趣可以读一下
"Tendency to replace whom with who[edit] （用who代替whom的趋势）
According to traditional prescriptive grammar,who is the subjective (nominative) form only,while whom is the corresponding objective form (like him is the objective form corresponding to he).However it has long been common,particularly in informal English,for the uninflected form who to be used in both cases,thus replacing whom in the contexts where the latter was traditionally used.
It was written in 1975 that:"Nearly half a century ago Edward Sapir predicted the demise of whom,showing at great length that it was doomed because it was 'psychologically isolated' from the objective pronouns me,us,him,her,them on the one hand,and the invariables which,what,that and where,when,how,why on the other."[3]
In 1978 the who–whom distinction was identified as having "slipped so badly that [it is] almost totally uninformative".[4] According to the OED (2nd edition,1989),whom is "no longer current in natural colloquial speech".Lasnik and Sobin argue that surviving occurrences of whom are not part of ordinary English grammar,but the result of extra-grammatical rules for producing "prestige" forms.[5]
According to Mair,the decline of whom has been speeded by the fact that it is one of relatively few synthetic (inflected) remnants in the principally analytical grammar of Modern English.[6] It has also been claimed that the decline of whom is more advanced in the interrogative case than in the relative case,this possibly being related to the degree of complexity of the syntax.[7]
However some prescriptivists continue to defend whom as the only "correct" form in functions other than the subject.[8] Mair notes that:"whom is moribund as an element of the core grammar of English,but is very much alive as a style marker whose correct use is acquired in the educational system [,where it is taught].[The use of whom] is highly restricted,but rather than disappear entirely,the form is likely to remain in use for some time to come because of its over prestige in writing."[9]
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