原谅我冒昧的给你写这封信.用英语怎么说

原谅我冒昧地给你写信:

Please excuse me for i'm taking the liberty of writing to you 这是比较地道的表示.

冒昧:make bold;venture;take the liberty

Excuse me for the letter I write to you (without speaking to you before)

The sun I took the liberty of writing this letter to you.