cho đến nay 
as yet, up until now [ cho ] : add, give; to, for; to say, claim; in order to; let, allow, permit
[ đến ] : from, beginning; to come, arrive; to, until, up to
[ nay ] : (1) this, these; (2) today, at present, nowadays, now, at this time
Most Common Compounds Set 1:
Most Common Compounds Set 2 :