если возможное налезание вронгов не волнует..
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<!DOCTYPE html>
<html>
<head>
<style>
p {line-height: 1.6em}
.correct {position: relative; color: #0f0}
.correct::before {content: attr(wrong); display: block; position: absolute; top: -.9em; left: -50%; right: -50%; text-align: center; color: #f00; text-decoration: line-through}
</style>
</head>
<body>
<p>
Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua.
<span class="correct" wrong="Sit">Dolor</span> <span class="correct" wrong="dolor">sit</span> <span class="correct" wrong="DOLOR">SIT</span>
Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua.
</p>
</body>
</html>
