The structures meaning "if..., then..."
You can use the following structures to say “if..., then...”:
倘若…，就… 
若…，就…
假设…，就…
假使…，就…
若…，就…
假设…，就…
假使…，就… Pay attention
These structures are used in written speech.
Examples
倘若一点儿音乐知识都没有，就会遇到困难
If you don’t know anything about music, you will face difficulties
tǎngruò yìdiǎnr yīnyuè zhīshì dōu méi yǒu, jiù huì yùdào kùnnán
The first part of a sentence refers to a condition. The second part of a sentence, which begins after 就, refers to a result.
Pay attention
就 is placed before a predicate.
Examples
假设您能用手接球，您就能轻易学会截击
If you can catch the ball with your hands, you will easily learn to play
jiǎshè nín néng yòng shǒu jiē qiú, nín jiù néng qīngyì xuéhuì jiéjí
假使你学过汉语，就容易找工作了
If you learn Chinese, it’ll be easy to find a job
jiǎshǐ nǐ xuéguò hànyǔ, jiù róngyì zhǎo gōngzuò le
就 can be replaced with 那 and 那么 .
and 那么 .Examples
假使一切能重新开始，那我绝不会选择这一条路
If I could start over again, I would never have chosen this path
jiǎshǐ yíqiè néng chóngxīn kāishǐ, nà wǒ jué bú huì xuǎnzé zhè yì tiáo lù
他说，若他是个英雄，那么那些走向未知的人们各个都是英雄
He said that if he is a hero, then all those who go into the unknown are heroes too
tā shuō, ruò tā shì ge yīngxióng, nàme nàxiē zǒuxiàng wèizhī de rénmen gè ge dōu shì yīngxióng
假设有人在桌子上摆一个铁球，那么这个铁球立刻就会朝着磁铁的方向滚动过去
If someone puts an iron ball on the table, then the iron ball will immediately roll towards the magnet
jiǎshè yǒurén zài zhuōzi shàng bǎi yí ge tiě qiú, nàme zhè ge tiě qiú lìkè jiù huì cháozhe cítiě de fāngxiàng gǔndòng guòqù