YOU SAID:

the thumbtack is dangerously sharp

INTO JAPANESE

画thumbは危険なほど鋭い

BACK INTO ENGLISH

The picture thumb is dangerously sharp

INTO JAPANESE

写真の親指は危険なほど鋭い

BACK INTO ENGLISH

The thumb of the photo is dangerously sharp

INTO JAPANESE

写真の親指が危険なほど鋭い

BACK INTO ENGLISH

The thumb of the photo is dangerously sharp