Translate

How do you say these two sentence as a girl to a guy

“can you speak English? If so, let’s hear”


And also. I want to say to him.
“I think you’re the coolest guy I have ever talked to.”

Bc the expression of the words in Japanese differs in age and position,
Q1 : How old are A and B?
Q2 : A is you or a character of story like comics or novels?
Q3 : Are there romantic emotions btw A and B, or just friends?
Q4 : What is the character of A? Serious?, Shy?, Gal?, Bokukko/Orekko?
Q5 : What level "cool"?

If both are school class mates and just friends,
B君って英語話せたっけ? もしそうなら、ちょっと聞いて?
B-kun-tte Eigo Hansetakke? Moshisounara, Chotto Kiite?

あなたが私が今まで話した中で一番イケてると思う。
Anata ga Watashi ga Imamade Hanashita naka de Ichiban Iketeru to Omou.

Copy to below both, then click speaker icon. (Micro版 is just smaller sound file)
http://voicetext.jp/
The 6th chara fr the left is the most natural, intonation and speed.

If Gal, like this.
お前さぁ、英語話せんの? そんならちょっと聞けよ。
https://en.wikipedia.org/wiki/My_First_Girlfriend_Is_a_Gal
https://en.wikipedia.org/wiki/Gyaru

I think the OP means "let’s hear you speak English".
Anyway, let's here what answers the OP offers.

Hey you guys. I’m a girl and I’ve recently started talking to this Japanese guy I’m interested in. I would love to surprise him with some Japanese words but of course he know that I don’t know that well. But we were talking and I wanted to ask him if he knows English good. And then I wanted to tell him that he’s the coolest guy I’ve ever talked with. And also that he seems different. If you guys can translate that for me as a girl to a guy. I would be happy (≧∀≦)

“can you speak English? If so, let’s hear”
I can't catch the meaning of the verb "hear" in your usage. what you want to "hear" ?
probably, you mean you want to speak with him, if he can speak English.
英語話せるなら、お話しましょう。
eigo wo hanaseru nara, ohanashi shimashou.

“I think you’re the coolest guy I have ever talked to.”
今まで会った人のなかで、一番かっこいいです。
imamade atta hito no naka de, ichiban kakko iidesu.

I guess OP wants to hear him speak English.
- Eigo wo hanasemasu ka? Hanaserunara, eigo de hanasu no wo kikasete kureru? (Can you speak English? If you can, won't you let me hear you speak it?