久知爱你已深深知爱你已久
[jiŭ zhī ài nĭ yĭ shēn shēn zhī ài nĭ yĭ jiŭ]
'Long known how deeply you've loved me for so long.' This implies that the person has already realized someone's long-standing deep affection towards themselves over a significant amount of time. The tone contains both acknowledgement and response to the long-term attention and care.