Welcome to the Brain Game, a five-days-a-week feature here on www.mentalfloss.com.

By adding one letter at a time (and rearranging the letters as necessary) to form new words, convert the word "I" into the word "ERSTWHILE." Good luck!

I
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E R S T W H I L E

Here is one SOLUTION.

ONE SOLUTION:

I > IS > SIT > THIS > SHIRT > THEIRS > WITHERS > WHISTLER > ERSTWHILE

Did you come up with a different solution? Please share it with us in the comments. Thanks for playing!