The clich "can't hold a candle to" has to do with comparing the worthiness of one person or thing to another's. But why? In the 16th century, before the advent of street lights, servants lit the way for their British masters, by candlelight indoors and by lantern or torch outdoors. These servants, called "linkboys," accompanied their masters down the street, holding a "link," or torch, to light the way. The job required very little skill. Therefore, if someone is not qualified to "hold a candle," they were unfit for the lowliest servile job.
Love is an egg
"No score" in tennis is announced as "love." Is that supposed to make the person who's losing feel better? It's much more likely that the usage has its origin in the French language.
Tennis dates back to 18th-century France. Nil, or nothing, is numerically zero, and the shape of a zero resembles that of an egg. French tennis players adopted their word for egg - l'oeuf - to announce "no score." (The American "goose egg" and British cricket-player's "duck's egg" indicate the same thing.) When tennis crossed the English Channel, l'oeuf was recast by British speakers to "love."
And speaking of tennis...
The origin of the word "tennis" is far less certain. The ancient Egyptian town of Tinnis has been offered, as it is famous for its linen, which was used to stuff tennis balls. But it's more likely that "tennis" is a corruption of the French expression "Tenez!" meaning "Attention!" or "Play!" One can imagine a player about to serve the ball alerting his opponent this way.
Why is a 'greenhorn' green?
This term for an inexperienced person or animal became popular at the turn of the century as a term for any newcomer to a trade, an Army recruit, or a recent immigrant to America. On the western frontier the expression was synonymous with any new arrival, man, or beast. But originally, the word came from the ox.
Oxen were among the first animals to be domesticated for farm work. They were difficult to train, however. Often, they were full-grown before they learned the simplest commands. A young animal whose horns were freshly sprouted, or "green," was untrained. Often its horns were covered with a fungus that gave them a greenish cast, making "greenhorn" more than figurative.