YOU SAID:

I think, that I broke my arm last night.

INTO JAPANESE

私は、昨夜の私の腕を壊したことと思います。

BACK INTO ENGLISH

I think it broke last night my arm.

INTO JAPANESE

それは最後の夜に私の腕を壊したと思います。

BACK INTO ENGLISH

I think it broke my arm last night.

INTO JAPANESE

それは最後の夜に私の腕を壊したと思います。

BACK INTO ENGLISH

I think it broke my arm last night.