Also, as well and too are adverbs and mean ‘in addition’.
Also is commonly used in writing, but is less common in speaking. Also occupies different positions in a sentence.
We use also in front position to emphasise what follows or to add a new point or topic:
It’s very humid. Also, you can easily get sunburnt.
[on the telephone]
OK, I’ll phone you next week and we can discuss it then. Also, we need to decide who will be going to Singapore.
We use also in the normal mid position for adverbs, between the subject and main verb, or after the modal verb or first auxiliary verb, or after be as a main verb. In this position, the meaning of also usually connects back to the whole clause that comes before:
She works very hard but she also goes to the gym every week.
I’ve been working in the garden this week, and I’ve also been reading a lot.
In end position, also normally connects two phrases. We use as well and too instead of also, in end position, especially in speech:
She contacted him in the office but he didn’t answer the phone. His mobile phone was silent also. (or His mobile phone was silenttoo. or … was silentas well.)
As well is much more common in speaking than in writing, and is more common in speaking than also.
As well almost always comes in end position:
[In a restaurant. Customer (A) is ordering from a waiter (B)]