I can speak more fluently and confidently when I talk with you.
**I can speak more fluently and confidently when I talk with you.**
「あなたと話すと、より流暢に自信を持って話せる」
fluently(流暢に)とconfidently(自信を持って)を合わせることで、スピーキング力が上がっている感覚を表現できます。
* **例文:**
I feel I can speak more fluently and confidently when I talk with you.
あなたと話していると、英語がもっとスラスラ出てきて自信も持てる気がします。