Tra từ also - Từ điển Oxford Advanced Learner 8th

also BrE [ˈɔːlsəʊ] NAmE [ˈɔːlsoʊ] adverb
(not used with negative verbs)in addition; too
• She's fluent in French and German. She also speaks a little Italian.
•rubella, also known as German measles
• I didn't like it that much. Also, it was much too expensive.
•Jake's father had also been a doctor (= both Jake and his father were doctors).
•She was not only intelligent but also very musical.

Word Origin:
[also] Old English alswā ‘quite so, in that manner, similarly’, composite of ↑all + ↑so.

Language Bank:
addition
Adding another item
▪ Bilingual children do better in IQ tests than children who speak only one language. In addition ▪ / What is more ▪, they seem to find it easier to learn third or even fourth languages.
▪ Learning another language not only ▪ improves children's job prospects in later life, but also ▪ boosts their self-esteem.
▪ Teaching children a second language improves their job prospects in later life. Other ▪ benefits include ▪ increased self-esteem and greater tolerance of other cultures.
Another ▪ / One further ▪ / One additional ▪ reason for encouraging bilingual education is that it boosts children's self-esteem.
▪ Studies suggest that bilingual children find it easier to learn additional languages. There is, moreover ▪, increasing evidence that bilingual children perform better across a range of school subjects, not just foreign languages.
▪ His claim that children find bilingual education confusing is based on very little evidence. Moreover ▪, the evidence he does provide is seriously flawed.
▪ Research has shown that first-language development is not impeded by exposure to a second language. Furthermore ▪, there is no evidence to support the claim that children find bilingual education confusing.

Which Word?:
also / as well / too
Also is more formal than as well and too, and it usually comes before the main verb or after be: ▪ I went to New York last year, and I also spent some time in Washington. In BrE it is not usually used at the end of a sentence. Too is much more common in spoken and informal English. It is usually used at the end of a sentence: ▪ ‘I’m going home now.’ ‘I’ll come too.’. In BrE as well is used like too, but in NAmE it sounds formal or old-fashioned.
When you want to add a second negative point in a negative sentence, use not...either: ▪ She hasn’t phoned and she hasn’t written either. If you are adding a negative point to a positive one, you can use not…as well/too: ▪ You can have a burger, but you can’t have fries as well.