don"t shine at tennis.

我不擅長打網球。

I am no good at it.

我對它不擅長。

My sister is no good at arithmetic.

我妹妹不擅長算術。

Lack of talent or ability.

不擅長，笨拙缺乏天資或能力

I"ve never learnt the trick of making friends easily.

我一向不擅長輕易交上朋友。

I wouldn"t say I was proficient at computer programing.

我看我並不擅長計算機程式設計。

I"m not very good at hacking but I"ll give it my best.

我不擅長安裝但是我會盡力。

He"s not very good at description.

他不大擅長描寫敘述.

He is not a good hand of write.

他不是一個擅長書法的人。

Not in my line.

這不是我所擅長期的