He as well as I ___(be) here.

is
as well as I 是附属部分

is

这是一个简单的句子, 但是as well as 连接的句子谓语动词
要与第一个主语一致.所以这句要用 is .

我刚高考完，这些基础很清楚

is
这是主谓一致问题。当主语后面跟有with, together with, like, except, but, no less than, as well as 等词引起的短语时，谓语动词与前面的主语一致。
例：He as well as I wants to go boating

is(就远原则)

am，就近

is，因为有as well as （除了），按就前原则。
同学信我的没错。祝你好运！