我们应该要对自己有自信。

Wǒmen yīnggāi yào duì zìjǐ yǒu zìxìn.

We should have confidence in ourselves.

我们要有自信，可是不要骄傲。

Wǒmen yào yǒu zìxìn, kěshì búyào jiāo'ào.

We need to have self confidence, but shouldn't be arrogant.

他们跟外国人说英语的时候越来越有自信了。

Tāmen gēn wàiguórén shuō Yīngyǔ de shíhou yuèláiyuè yǒu zìxìn le.

They became more and more confident when talking with foreigners in English!