You will understand perfectly that I cannot at present correspond with your father.
你一定完全了解,我目前不能写信给令尊。
The translator should understand perfectly the content and intention of the author whom he is translating.
译者须充分理解内容并完全明白作者的意图。
Owing to heavy commitments, they cannot advance delivery from June to April but they understand perfectly that July is the selling season for shirts in your market.