我想不起他的名字了。

Wǒ xiǎngbuqǐ tā de míngzi le.

I can’t remember his name.

我突然想起还有一个重要的电话没打。

Wǒ tūrán xiǎngqǐ hái yǒu yí gè zhòngyào de diànhuà méi dǎ.

I suddenly remembered that there is an important phone call I haven’t made.

我常常想起在中国学习的那一年。

Wǒ chángcháng xiǎngqǐ zài Zhōngguó xuéxí de nà yì nián.

I often think of that year when I studied in China.