The typical answer to this is “I am,” but some argue that it’s not a complete sentence. However, if someone asked a man named Rupert if he was Rupert, he could reply, “I am” and it would make a complete sentence in my book.
But that’s not the whole answer. There is an even shorter sentence using an imperative with an implied subject (how’s that for an English terminology-filled sentence?) With “Go,” the “you” is implied. For example, if your wife wanted you to go with her to pick up some donuts and you were busy, she might say, “I really want to get some donuts, I’m starving!” and you might reply, “Go!” The implication being you never wanted to get donuts in the first place because you like ice cream more anyway and if you’re busy you’re probably doing something worthwhile and important and can’t be disturbed for such trivial matters as acquiring sweet pastries with holes in them, no matter how much of a waste of time your wife says your pursuits are. In short, “Go” is the shortest sentence in the English language that also has the longest implied meaning. Do you want to get get some ice cream? Go!
Ava pointed out in the comments that No is another viable alternative.
A black dog is sleeping in the middle of a black road that has no streetlights and there is no moon. A car coming down the road with its lights off steers around the dog. How did the driver know the dog was there?
Mary was out riding a frisky pony in a meadow by the sea when the bridle came loose. The animal shook it off and started to gallop full speed toward the ocean, paying no attention to Mary’s yelling to slow down. She couldn’t bear to jump off and lose her beloved pony, so she stayed on and hoped for the best. When the cliff loomed ahead of her, she knew she had to stop the pony. How did she do it?
People speak through me, yet I do not make a sound. People can sell me, yet I have many clones. I can bring you laughter between breakfast and tea, Yet I can also break your heart easily. I cover the earth like trees of old, Whose leaves can blind and yet enfold.
A book. Authors can speak to you through a book, yet the book makes no sound. Books are sold and have many duplicate copies. A book can bring the reader to tears and laughter, they span the globe and the leaves of a book (a single sheet in a book is called a leaf) can get you wrapped up in the story that you’re unaware of what’s going on around you.
Brief (or briefs). A legal brief is a short outline of the arguments in a court case, briefs are worn by men to cover their privates. Brief also means to not last long and brief rhymes with grief, a kind of misery.
My days are in the summer When you’ll eat me when I’m hot In fact I’ll even eat myself Where battles tough are fought But when you find me in a fight ‘Twill be high in the sky And if you catch me napping I suggest you let me lie When you’re bad come to my house From Ma get thoughts profound Am I big or am I small? Some say I’m just a pound.
Every dawn begins with me At dusk I’ll be the first you see And daybreak couldn’t come without What midday centers all about Daises grow from me, I’m told And when I come, I end all cold But in the sun I won’t be found Yet still, each day I’ll be around