谢谢！Luan Yu

我去机场接我哥哥。 (I went to/am going to/will go to)airport to pick up my brother. There's no tense in Chinese,when this situation happens depends on the scene which the speaker is talking in. 我到机场接我哥哥。 到means arrive at. the meaning of this sentence is similar as the first one. 我在机场接到我哥哥。 I have picked up my brother at the airport. so 到means you have finished this action and the result is you brought your brother back. Another point that I want to remind you, 请回答我一个问题。 (please answer me a question) or 请允许我问一个问题。 (let me ask you a question)

接到 means you have finished the action of 接