As you progress through high levels, words will have a lot of possible options, sometimes more than could be fit on the screen, and keep things readable.
Rather than try to fit in every single possible word, high levels have a certain amount of words turned into Extra Words for that level.
Sometimes the Extra Words for that level may include short, common words that were required in previous levels. In this case, they're an easy way to bolster your totals towards the next Extra Word Goal and get some extra Golden Acorns.
Words that are turned into Extra Words via this method still fall under the rule that a word can only be submitted as an Extra Word once - if it's an Extra Word in a future level, finding it again will let you know that it's already been included as an Extra Word.
Rather than try to fit in every single possible word, high levels have a certain amount of words turned into Extra Words for that level.
Sometimes the Extra Words for that level may include short, common words that were required in previous levels. In this case, they're an easy way to bolster your totals towards the next Extra Word Goal and get some extra Golden Acorns.
Words that are turned into Extra Words via this method still fall under the rule that a word can only be submitted as an Extra Word once - if it's an Extra Word in a future level, finding it again will let you know that it's already been included as an Extra Word.