YOU SAID:

I saw two ducks go for a swim on my way to the store

INTO JAPANESE

2羽のアヒルが店に向かう途中で泳ぎに行くのを見ました

BACK INTO ENGLISH

I saw two ducks go swimming on the way to the store

INTO JAPANESE

2羽のアヒルが店に行く途中で泳ぎに行った

BACK INTO ENGLISH

Two ducks went swimming on the way to the store

INTO JAPANESE

2羽のカモが店に向かう途中で泳ぎに行きました

BACK INTO ENGLISH

Two ducks went swimming on the way to the store