YOU SAID:

I am amazed at the sheer volume of people at the concert.

INTO JAPANESE

コンサートの人数の多さに驚いています。

BACK INTO ENGLISH

I am surprised at the large number of people at the concert.

INTO JAPANESE

コンサートにはたくさんの人が来てびっくりしました。

BACK INTO ENGLISH

Many people came to the concert and were surprised.

INTO JAPANESE

多くの人がコンサートに来てびっくりしました。

BACK INTO ENGLISH

Many people were surprised to come to the concert.

INTO JAPANESE

多くの人がコンサートに来て驚いた。

BACK INTO ENGLISH

Many people were surprised to come to the concert.