YOU SAID:
He wouldn't know if someone was up him sideways with an armful of deck chairs
INTO JAPANESE
彼は誰かがデッキチェアを一杯持って横向きになっていたかどうかわからなかった
BACK INTO ENGLISH
He didn't know if someone was lying sideways with a full deckchair
INTO JAPANESE
彼は誰かがフルデッキチェアで横になっているのかどうか知りませんでした
BACK INTO ENGLISH
He didn't know if anyone was lying in a full deck chair
INTO JAPANESE
彼は誰かがフルデッキチェアに横たわっているかどうか知りませんでした
BACK INTO ENGLISH
He didn't know if anyone was lying in a full deck chair
This is a real translation party!