they are people that check your writing for errors.
1- <span>The ancient Chinese board game “Go” is invented long before there was any writing to record its rules. A game from the impossibly distant past has now brought us closer to a moment that once seemed part of an impossibly distant future: a time when machines are cleverer than we are.
<u>Because it's an action that started and finished in the past, this should read </u><u>was</u><u> (Simple Past)</u>
2- </span><span>For years, Go was considered the last redoubt against the march of computers. Machines might win at chess, draughts, Othello, three-dimensional noughts and crosses, Monopoly, bridge, and poker. Go, though, is different.
<u>This continues the same line of mistake as the first paragraph. Because it's referencing something that already happened ("Go was considered...), this should read </u><u>was</u><u> (Simple Past).</u>
The game required intuition, strategising <u>and</u> character reading, along with vast numbers of moves and permutations. According to legend, it was invented by a Chinese emperor to teach his subjects balance and patience: qualities unique to human intelligence.
<u>The conjunction and is used before the last element in a list. In this case, this word should be substituted by a comma because <em>character reading</em> is not the last element on that list.</u>
3- </span><span>This week, though, a computer called Alpha Go <u>defeats</u> the world’s best player of Go. It did so by “ learning” the game, crunching through 30 million positions from recorded matches, reacting and anticipating. It <u>evolves</u> as a player and taught itself.
That single game of Go marks a milestone on the road to the “technological singularity”, the moment when artificial intelligence becomes capable of self-improvement and learns faster than humans can control or understand.</span><span>
<u>These should read defeated ... evolved. This continues the same line of thought on subject-verb agreement. If it's talking about a past event, and the rest of the paragraph sustains that idea, then these verbs should be in Simple Past.</u></span><span>
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