Present Perfect
+Subject +have/has+Verb3/Ved
-Subject +haven't/hasn't+Verb3/Ved
?(Wh)+Have/Has+subject+Verb3/Ved?
Ever,never,since2007,lately,for 2 years,just,yet,already,recently,so far...
+He has already checked a file.
-He hasn't checked a file yet.
?Has he checked a file yet?