1. 抱怨;发牢骚
    If you complain about a situation, you say that you are not satisfied with it.

    e.g. Miners have complained bitterly that the government did not fulfill their promises...
           矿工们愤愤不平地抱怨说政府没有履行诺言。
    e.g. The American couple complained about the high cost of visiting Europe...
           这对美国夫妇抱怨到欧洲旅行的花销太高。

2. 诉说有…病痛;主诉
    If you complain of pain or illness, you say that you are feeling pain or feeling ill.

    e.g. He complained of a headache.
           他说头痛。