あいつは手強い相手だ。

あいつは手強い相手だ。

He is a formidable opponent.

あいつは手強(てづよ)い相手(あいて)だ。

Aitsu wa tezuyoi aite da.

彼奴 (あいつ、きゃつ、かやつ、あやつ)

he; she; that guy

は (は)

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

手強い (てづよい)

strong; resolute; firm; strict

相手 (あいて)

companion; partner; company; other party; addressee; opponent (sports, etc.)

だ (だ)

be; is; indicates past or completed action; indicates light imperative

Readings: シュ、ズ、て、て-、 -て、た-

Meaning: hand

Readings: キョウ、ゴウ、つよ.い、つよ.まる、つよ.める、し.いる、こわ.い

Meaning: strong

Readings: ソウ、ショウ、あい-

Meanings: inter-, mutual, together, each other, minister of state, councillor, aspect, phase, physiognomy