Synonyms for Soon:

adj.

•early (adjective)
early, promptly.

adv.

•in the near future (adverb)
early, forthwith, shortly, quickly, in due time, promptly, presently, directly, before long.
•soon (adverb)
in a while, in due time, quickly, before long, directly, shortly, presently.

adv

•early (adverb)
before long.
•soon (adverb)
in a while, presently, directly, shortly, before long, in due time.

n.

imminent, someday, forthwith, in the short run/term, in no time (at all), at the earliest/first opportunity, just, quickly, close, around the corner, any day/moment etc. now. •early (noun)
early, promptly.
•in the near future (noun)
in a while, in due time, quickly, before long, forthwith, shortly, presently.

Other synonyms:

just. early. close.

Usage examples for soon

1. Won't you come over soon and see us? – Frank's Campaign or the Farm and the Camp by Horatio Alger, Jr.

2. As soon as I have found them I will come back. – Old Peter's Russian Tales by Arthur Ransome

3. That's why I have come again so soon – Will Warburton by George Gissing