also&just問題

根據 Michael Swan o既 Practical English Usage International Student's Edition (2001) adverb 條第三點 (p. 23)，簡譯如下：
Focusing Adverbs
這些 adverbs 「指向（point to）」句子中的一部份。例子有 also, just, even, only, mainly, mostly, either, or, neither, nor。位置：中間（mid-position）〔根據 p.25 解釋，為通常置於助動詞之後，is/am/are/was/were後及其他動詞之前〕。
有關 also 同 just o既例子有：
She's my teacher, but she's also my friend.
Your bicycle just needs some oil - that's all.
所以：
1. he is also
2. he can also
3. he is also writing
本書仲有好多關於 mid-position o既其他說明，舊版如果書展有應該幾十蚊有交易，不妨考慮呢本好書。

1. and 2. and 3. all correct

also can be put before and after verbs

for JUST, it can be put before or after verbs

eg. he is just a young boy
I just work for one company (I work jut for one company is also correct)