这个动词可用可不用。The verb may be expressed or understood.它是可用可不用的，有时用了分号会使句子更容易理解。It's optional, but may on occasion make the sentence more understandable.P.S.可参考以上例句
可用可不用的英文翻译 Available for use 可用 [词典] available; usable; do; [例句]实质性证据的性质和可用性毋庸讨论。The nature and availability of material evidence was not to be discussed
