How to say "if" in Chinese
"If" can be expressed in two ways in Chinese — with one word or with a construction.
"If" with one word
There are different ways of expressing "if" in Chinese:
如果 
要是
倘 or 倘若
假如
要是
倘 or 倘若
假如 Pay attention
如果 is used more often than the others.
如果 and 要是 are used in spoken language, while 假如 and 倘若 are used in written speech.
These words are used in the first part of a compound sentence to introduce a condition.
The result is described in the second part.
If there is the same verb in both parts of the sentence, then these words follow the verb.
If there are two different verbs, then they go before the first verb at the beginning of a sentence.
Examples
你要是不懂，可以随便提问
If you don't understand, feel free to ask questions
nǐ yàoshi bù dǒng, kěyǐ suíbiàn tíwèn
如果你病了，体温会波动
Your body temperature fluctuates if you are sick
rúguǒ nǐ bìng le, tǐwēn huì bōdòng
倘若我们再次见面，我希望他还记得我为他做的事
If we meet again, I hope he remembers what I did for him
tǎngruò wǒmen zàicì jiànmiàn, wǒ xīwàng tā hái jìde wǒ wèi tā zuò de shì
We often use the adverbs 就 , 那 , or 那么 in the second part of the sentence.
就 goes before the verb, while 那 and 那么 are placed at the beginning of the sentence, before the subject and the verb.
, 那 , or 那么 in the second part of the sentence.
就 goes before the verb, while 那 and 那么 are placed at the beginning of the sentence, before the subject and the verb.Examples
如果明天下雨，那么远足就要延期了
If it rains tomorrow, the hike will be postponed
rúguǒ míngtiān xiàyǔ, nàme yuǎnzú jiù yào yánqí le
倘可以回到中国了，我就会赚很多钱
If I could go back to China, I would make a lot of money
tǎng kěyǐ huí dào zhōngguó le, wǒ jiù huì zhuàn hěn duō qián
假如 usually describes hypothetical situations which are not true at the present time and means “let’s assume that...”.
Examples
假如我们分手了，你会恨我吗？
Would you hate me if we broke up?
jiǎrú wǒmen fēnshǒu le, nǐ huì hèn wǒ ma
"If" with a pattern
The words 如果, 要是, 倘若 and 假如 are often used as part of a construction with the same meaning of ”if“.
If there is 如果, 要是 or 倘若 at the beginning of the first part of the sentence, then we put 的话 at the end of the sentence.
at the end of the sentence.Scheme
如果/要是/倘若
condition
的话
result
Pay attention
We often use 就 before predicate in the second part of the sentence.
Examples
如果你方便的话，和我们吃顿饭吧
Have a meal with us if it's convenient for you
rúguŏ nĭ fāngbiàn de huà hé wŏmen chī dùn fàn ba
要是你想妈妈的话，就给妈妈打电话吧
If you miss your mum, call her
yàoshi nǐ xiǎng māma de huà, jiù gěi māma dǎ diànhuà ba
假如我是你的话，我就会抓住这个机会
If I were you, I'd take this chance
jiǎrú wǒ shì nǐ de huà, wǒ jiù huì zhuāzhù zhè ge jīhuì
The construction can be shortened to 的话 in spoken language. The meaning is the same:
Examples
这样的话，就谢谢了
In that case, thank you
zhèyàng de huà jiù xièxie le
你要的话就拿去吧
Take it if you want
nǐ yào de huà jiù náqù ba
Pay attention
“If" can also be expressed with the conjunction 万一 and the construction that goes with it ↓
and the construction that goes with it ↓