YOU SAID:
Tony went to a party with a flying duck
INTO JAPANESE
トニーは空飛ぶアヒルとパーティーに行きました
BACK INTO ENGLISH
Tony went to a party with flying ducks
INTO JAPANESE
トニーは飛ぶアヒルとパーティーに行きました
BACK INTO ENGLISH
Tony went to the party with a flying duck
INTO JAPANESE
トニーは空飛ぶアヒルとパーティーに行きました
BACK INTO ENGLISH
Tony went to a party with flying ducks
INTO JAPANESE
トニーは飛ぶアヒルとパーティーに行きました
BACK INTO ENGLISH
Tony went to the party with a flying duck
it is unlikely that this phrase will ever reach equilibrium