formerly是時間狀語嗎

是時間狀語，例如：

1、I learnt that the house had formerly been an inn.我得知這座房子以前是家客棧。

2、Many products formerly made of metal now are made of plastic.以前用金屬製造的許多產品現在都用所料製造了。

3、formerly， sea power gave big nations influence over others.以前海軍的力量能使強國影響其它國家。