How do you say in French: not to be able to hold a candle to somebody?

Answer 1

ne pas arriver à la cheville de quelqu’un

Answer 2

Just to complete Andre's answer: it is an expression, an expression that we don't use in France with a candle so if you translate "word by word"

"Not to be able to hold a candle to somebody"= "Ne pas pouvoir tenir une bougie à quelqu'un" (but clearly noone will say that in France)

French people will effectively say to express the same idea:

"ne pas arriver à la cheville de quelqu’un"

which means is you translate word by word: "not to reach someone's ankle"