Meaning of zhǐ shì:
zhǐ shì
只是
Adverb
merely; only; just; nothing but; simply
Zhè zhǐshì yī gè wùhuì.
这只是一个误会。
This is just a misunderstanding.
Wǒ zhǐ shì kāi gè wánxiào.
我只是开个玩笑。
I am simply making a joke.
Conjunction
but; however
Tā suīrán lèi le, zhǐshì tā hái děi jìxù gōngzuò.
他虽然累了,只是他还得继续工作。
Although he is tired, he still has to continue working.