One of the greatest problems in translating or understanding CJ faced by those familiar with MJ is the proliferation of “false friends” with whom they share kanji or other roots. Some of the more common — and more troublesome — examples are:

Classical Japanese Word	Classical Japanese Meaning	Modern Japanese Meaning
tameshi	example	test/attempt
sunawachi	soon, immediately	“in other words…”
okashi	interesting, beautiful	funny
utsukushi	beloved, attractive	beautiful
mezamashi	amazing, interesting	waking-up
ashita	morning	tomorrow
mezamashi	mezamashi	mezamashi
mutsukashi	unpleasant, eerie	difficult
okonau	to do; to hold Buddhist services	to occur
nonoshiru	to shout, to call out	to revile, to abuse
ari	to be (people & things)	to be (things only)

      Another problem is the proliferation of totally different terms and words for common ones long-since internalized from years of working with Modern Japanese. Some of the more frequent ones are:

Modern Japanese Word	Classical Japanese Word	Meaning
a, ano	ka, kano	that (over there)
sore	sa	that
aruku	ariku	to walk
muzukashii	katashi	difficult
tegami	fumi	letter (correspondence)

     Other frequent, useful words either do not exist in Modern Japanese, or are totally unlike any related concept in Modern Japanese, although the same kanji may be used (with a different reading) for the same concept. Some examples:  

Classical Japanese Word	Meaning
yamugotonashi	exalted; unable to be ignored
ito	very
ikade	in what manner; however (rhetorical, with Q)
saranari	of course; it goes without saying
atenari	exalted; first rate
imiji	great; impressive
kokoroushi	difficult; unappreciated; unpleasant
ashi	evil; bad; wrong
itsuku	to revere; to worship