Semicolons

Many companies make sugar-free soft drinks, which are flavored by synthetic chemicals; the drinks usually contain only one or two calories per serving.

Many companies make sugar-free soft drinks, which are flavored by synthetic chemicals, the drinks usually contain only one or two calories per serving.

Mr. Leyland played the viola professionally for many years; and he now conducts a community orchestra.

Mr. Leyland played the viola professionally for many years, and he now conducts a community orchestra.

The crabgrass was flourishing; but the rest of the lawn, unfortunately, was dying.

The crabgrass was flourishing, but the rest of the lawn, unfortunately, was dying.

The hill was covered with wildflowers; it was a beautiful sight.

The hill was covered with wildflowers, it was a beautiful sight.

As I turned around, I heard a loud thump; for the cat had upset the goldfish bowl.

As I turned around, I heard a loud thump, for the cat had upset the goldfish bowl.

The artist preferred to paint in oils; he did not like watercolors.

The artist preferred to paint in oils, he did not like watercolors.

The house was clean, the table set, and the porch light on; everything was ready for the guests' arrival.

The house was clean, the table set, and the porch light on, everything was ready for the guests' arrival.

He looked carefully in the underbrush; but he failed to notice the pair of green eyes staring at him.

He looked carefully in the underbrush, but he failed to notice the pair of green eyes staring at him.

The foundations of the house had been poured; however, to his disappointment, nothing else had been done because of the carpenters' strike.

The foundations of the house had been poured, however, to his disappointment, nothing else had been done because of the carpenters' strike.

The computer could perform millions of operations in a split second; however, it could not think spontaneously.

The computer could perform millions of operations in a split second, however, it could not think spontaneously.

I thought registration day would be tiring; but, I didn't know I'd have to stand in so many lines.

I thought registration day would be tiring, but I didn't know I'd have to stand in so many lines.

The snowstorm dumped twelve inches of snow on the interstate; subsequently, the state police closed the road.

The snowstorm dumped twelve inches of snow on the interstate, subsequently, the state police closed the road.

The suspect said that he had never met the victim; however, the detective knew that he was lying.

The suspect said that he had never met the victim, however, the detective knew that he was lying.

San Francisco is my favorite city; in fact, I plan to spend two weeks there this summer.

San Francisco is my favorite city, in fact, I plan to spend two weeks there this summer.

Juan didn't think he could win the race; yet it was worth a try.

Juan didn't think he could win the race, yet it was worth a try.