CEDICT
if
Wiktionary
假設、倘若。《儒林外史.第三九回》:「設若這個人還不能救你,我今日說破這個話,連我的性命只好休了!」也作「設令」、「設使」。
重編國語辭典
如果,假如
維基詞典
Imagine that you have a time machine.
Imagine what it would be like if you had a time machine.
Source: Tatoeba