Pressed on immigration themes in an earlier speech at a press conference during Ukip's spring conference in Torquay, Mr Farage denied he felt people should be forced to speak English on trains.
But the Ukip leader said: "I got the train the other night, it was rush hour, from Charing Cross.
"It wasn't until after we got past Grove Park that I could hear English being audibly spoken in the carriage. Does that make me feel slightly awkward? Yes.
"I wonder what's really going on.
"That does not mean one is anti immigration. We're not anti immigration, we want immigration but we do absolutely believe we should be able to judge it both on quantity and quality."
In his earlier speech, Mr Farage said that in scores of cities in a short space of time the country has become "unrecognisable".