as well ：一般不用否定句，通常放在句末，強(qiáng)調(diào)時(shí)可放在句中。
either ：用于否定句，放在句末，之前加逗號(hào)。
likewise ：是書(shū)面語(yǔ)用詞。
柯林斯高階英漢雙解學(xué)習(xí)詞典釋義
ADV
而且;還;此外
You can use also to give more information about a person or thing, or to add another relevant fact.
例句
It is the work of Ivor Roberts-Jones, who also produced the statue of Churchill in Parliament Square...這是艾弗·羅伯茨-瓊斯的作品，他還創(chuàng)作了議會(huì)廣場(chǎng)上的丘吉爾塑像。He is an asthmatic who was also anaemic...他是個(gè)曾患貧血癥的哮喘患者。
ADV
也；亦
You can use also to indicate that something you have just said about one person or thing is true of another person or thing.
例句
His father, also a top-ranking officer, had perished during the war...他的父親，也是位高級(jí)軍官，在戰(zhàn)爭(zhēng)中犧牲了。We have been working very hard, and our families have also worked hard...我們一直很努力工作，并且我們的家人也是如此。
英漢詞典釋義
adv.
也, 同樣, 并且，此外
You'll have to get a passport, and you'll also need a visa.你必須申辦護(hù)照, 同時(shí)還需要有簽證。I am also writing a short story.我也寫(xiě)短篇小說(shuō)。The son has gone also.兒子也去了。She not only plays well, but also writes music.她不僅很會(huì)演奏, 而且還會(huì)作曲。