1. sometimes常可用于句首。如：

Sometimes she comes late. 有時(shí)她來得晚。

Sometimes she didn’t agree with me. 有時(shí)她和我意見不一致。

Sometimes we get a lot of rain in August. 有時(shí)在8月份雨水很大。

2. often用于句首時(shí)，通常表示強(qiáng)調(diào)，且其前一般有quite, very修飾。如：

Very often he comes in late. 他常常遲到。

Quite often the phone rings when I’m in the bath. 電話經(jīng)常在我洗澡時(shí)響。

3. usually有時(shí)也用于句首，其前不用修飾語。如：

Usually I get up early. 我平時(shí)起得早。

Sometimes he comes by bus, but usually he comes by taxi. 有時(shí)他坐公共汽車來，不過他通常還是打的來。

Usually cooking pots have two small handles but pans have one long handle. 通常地深底煮鍋有兩只把手而平底鍋只有一個(gè)長長的把手。

4. always一般不用于句首，除非是用在祈使句中。如：

Always remember this. 請時(shí)刻記住這一點(diǎn)。

Always look in the mirror before starting to drive. 一定要先看看反光鏡再開車。

另外，never也可用于祈使句的句首。如(from www.)：

Never tell him the news. 千萬不要告訴他這消息。

Never ask her about her marriage. 決不要問她結(jié)婚的事。

5. 在正式文體中，表示否定意義的副詞seldom, never可位于句首，但此時(shí)其后要用倒裝語序。如：

Seldom has there been such a happy meeting. 過去很少有過這樣愉快的會議。

Never did he think the book would be finished so soon. 他可沒想到這本書會這么快看完。