Transitions: They’re those glasses that can turn into sunglasses, right?
Well, yes. But the term also refers to those phrases writers use to connect their thoughts together into something coherent. Without them, essays, articles and news releases would be a jumble of quotes, ideas and anecdotes, left to the reader to assemble into a narrative of some sort.
Not all transitions are created equal—try using “such has been” in a piece of modern writing, to stick with my Declaration of Independence kick here—and it’s worth knowing the when, where and how for some of the most common transitional words and phrases.
And so/In summation/In conclusion: Outside of formal writing—a research paper, speech, or perhaps an earnings report—an indication that you’re getting toward your conclusion, and perhaps mercifully wrapping this thing up, generally isn’t necessary. You don’t really have to announce your point, and if you do, it should come well before the end. So if you feel the need to start a sentence near the end of what you’re writing with an “and so,” you may want to consider reworking the beginning.