I can't think of how to say it in English. Just give me a second to think about it.
I can't come up with the right words in English. I just need a moment to figure it out.
この場合、次のような言い方ができます。
ーI can't think of how to say it in English. Just give me a second to think about it.
「英語での言い方が思いつかないから、ちょっと考えさせて」
to think of ... で「思いつく」
ーI can't come up with the right words in English. I just need a moment to figure it out.
「ぴったりの英語が浮かばない。考える時間をちょっとちょうだい」
to come up with ... で「思いつく」
ご参考まで！
カナダ 
