若语境是关心朋友,口头提示,可以说：Watch out, don't slip.
写警告标语时,英文标语都是命令句,把「slip」字当重点动词写出来的话,很容易令老外误会「请摔倒」.所以重点动词不是slip,是「留神」Beware.
如在室内：
Beware of slippery floor
Beware of uneven floor
如在户外:
Beware of slippery ground (地面) / road (路面)
Beware of uneven ground
小心摔倒用英语怎么说?