相识11年 英语怎么说

"We have known each other for 11 years" is the most common way to express this idea in English. The phrase "have known" is a verb phrase in the present perfect tense, which is used to describe an action that began in the past and continues up until the present time. The word "each" is used to indicate that both the speaker and the person they are speaking to have known each other for the same length of time.
Here are a few example sentences using this phrase:
"We have been friends for 11 years now. Time really flies, doesn't it?"
"It's hard to believe that we have known each other for 11 years. It feels like just yesterday that we met."
"I'm so grateful to have a friend like you. We have known each other for 11 years and I feel like I can always count on you."
I hope this helps!