YOU SAID:

the dog walked up the stairs and sat on the long red sofa

INTO JAPANESE

犬は階段を上がって、長い赤いソファに座りました

BACK INTO ENGLISH

The dog climbed the stairs and sat on the long red sofa

INTO JAPANESE

犬は階段を登って、長い赤いソファに座った

BACK INTO ENGLISH

The dog climbed the stairs and sat on the long red sofa