YOU SAID:

I was walking my dog when it began to rain.

INTO JAPANESE

雨が降り始めたとき私は犬を散歩させていた。

BACK INTO ENGLISH

When it started to rain, I was taking my dog for a walk.

INTO JAPANESE

雨が降り始めたとき、私は犬を散歩に連れて行っていました。

BACK INTO ENGLISH

When it began to rain, I was taking my dog for a walk.

INTO JAPANESE

雨が降り始めたとき、私は犬を散歩に連れて行っていました。

BACK INTO ENGLISH

When it began to rain, I was taking my dog for a walk.