你是我的竞争对手。

Nǐ shì wǒ de jìngzhēng duìshǒu.

You’re my competitor.

他是我在比赛中的最强对手。

Tā shì wǒ zài bǐsài zhōng de zuì qiáng duìshǒu.

He is my strongest opponent in the competition.

对手的实力非常强大，我们需要加倍努力。

Duìshǒu de shílì fēicháng qiángdà, wǒmen xūyào jiābèi nǔlì.

The opponent's strength is very powerful, we need to double our efforts.