偶爾：

　　occasionally

　　e.g. There's no harm in your staying up late occasionally.

　　偶爾晚睡并無妨害。

　　sometimes

　　e.g. I differed with my partner sometimes, but we usually agree.

　　我有時與我的伙伴爭論，但我們通常是一致的。

　　once in a while

　　e.g. He comes to our room for a chat every once in a while.

　　他偶爾來我們房中閑談。

　　on some occasions

　　e.g. Therefore they kept the children on some occasions giving the "seller" a gift in return.

　　因此，有些時候,他們就會給這些“出售者”禮物作為回報(bào)，留下孩子們。