There is no past tense for the word left. You can use already left for it.
myself
You should recycle that plastic bottle instead if throwing it away.
Instead of using the word challenging you can use the word gifted, special, special gifted.
Instead of using I in a essay paper what word do you use?
Grey and Gray are both the same word and can be interchanged in most cases.
Will, when, why, it, can
or
mixture
I have a stomach ache.
Myself
are
It is inappropriate to use xeroxed in a sentence. The word Xerox is a proper noun and a trade marked word owned by the Xerox Corporation. It is not and should not be used as a verb.There is a perfectly suitable short word that can be used instead. That word is copy. You could use it as, "I copied the table of contents of the book." If you need really high precision, use the longer word photocopy, instead.