What is the part of speech of 微 in the following? A dictionary says it's a verb while others say it's an adverb. Do these claims hold water?
"微" means "no", or "without" (無, 沒), as indicated in 國語辭典:
if it's not / without (微) mr 管 (管仲), . . .
in 論語注疏 卷十四 by 何晏 (魏)
it was marked:
There is an important characteristic in Chinese language: it often omits grammatical functors and particles. This phenomenon is extremely frequently seen in Classical Chinese, and still sometimes seen in Modern Vernacular Chinese.
Some examples in Modern Vernacular Chinese
OK, now let me answer the question.
Modern Vernacular Chinese:
If there were not Guanzhong, I would dishevel the hair and wear the clothes to the left.
Consequently, 微 is the adverb “not”.
微 is here analogous to 無 or 沒, and thus can be considered a verb. Using 没有A，就B to mean "if we did not have A, then B would happen" is still a common phrase in modern Chinese.
微 can also be an adverb, but it has a different meaning ("a little" rather than "not", as in 微笑).The sentence structure in your question also appears with other verbs, so it does not depend on 微's function as an adverb:
說曹操，曹操就到 (if you speak of Cao Cao, he will appear)
The main reason the sentence in your question is translated differently from other examples is because there is no good way to translate 無 or 微 into English as a verb.