not only...but also一般疑问句谓语动词的取决

not only...but also 中 按就近原则,离谁最近,就以谁来判断单数还是复数!
这里离he更近,所以用has.
如果是陈述句：not only he but also his friends have been to NewYork
注意此时是have,因为离his friends更近