During my F1 visa interview in the United States, I concealed that my grandfather was in the United States and was considered a liar. Will this affect my future immigration?

Very possible. Because a friend of mine signed a visa to go to the United States. He had signed a visa to go there once before, but he didn't go because he had something to do at home, so he signed the visa a second time. He had already arrived in the United States. When he was entering customs, he was asked if he had obtained a visa before. He didn't know why but said no. . . result. . I will never be able to set foot in the United States again for the rest of my life. Later he went to England. Why do you lie? The most important thing for foreign countries is credibility. If he doesn't find out you'll be fine, once he finds out you lied. .

hehe! Good luck