When you lean the cover for the bathtub against the wall it's easy to knock it over, so be careful.
When you put the bathtub cover against the wall it can get knocked down, so watch out.
ーWhen you lean the cover for the bathtub against the wall it's easy to knock it over, so be careful.
「風呂の蓋を壁に立てかけると、倒れやすいから気をつけて。」
lean ... against ~ で「〜に…を立てかける・もたせかける」
ーWhen you put the bathtub cover against the wall it can get knocked down, so watch out.
「風呂の蓋を壁に立てかけると倒れることがあるから、気をつけて。」
put ... against ~ でも「〜に…を立てかける」という意味になります。
bathtub「風呂釜・バスタブ」
cover「蓋」
knock ... over / know ... down 「…を倒す」
be careful / watch out 「気をつけて」
ご参考まで！
カナダ 
