Present: "He leads me to believe in grammatical rigor."

Past: "She led me to that conclusion long ago."

Past, growing popular but historically incorrect: "She lead me to that conclusion long ago."

Noun: "I licked the sweet lead off the wall."

Also noun: "After six rounds of chess-boxing-sprinting, it was not clear to either of the participants who had the lead."

Also also popular but historically incorrect noun: "We have eighty thousand lead-free ornaments on this wall, each lit by an individually-addressable led."