Why is there a 'は' in these sentences, forming double particles?


>   1. 家で **は** 勉強できません。図書館でも勉強できません。
>   2. 東京に **は** 、たくさん人がいます。
>

Can I drop the **は** in these two sentences?




This is the _contrastive_ は. This can be readily seen in the first sentence
where emphasis is being placed on where in particular the individual is unable
to study: neither at home nor in the library. This contrasts with other places
where one might be able to study.

In the second sentence, attention is being drawn to Tokyo itself. Other places
may not, by comparison, have so many people.

If in the first example, it had been written,

> 家で勉強できません。図書館で勉強できません。

This sounds a bit mechanical. "I can't study at home. I can't study in the
library." The listener might be thinking, "why are you telling me this?"

With は and も

> 家では勉強できません。図書館でも勉強できません。

this accomplished what we would accomplish in English by placing audible
emphasis on "at home" and on "nor at the library" ( _nor_ corresponds with も).
We expect these places to be good places to study; the use of は and も help
clarify for the listener why they should care. If I wanted to convey this
emphasis in written English, I could express this sentence as

> I can neither study at home; nor can I study in the library.

This could have been expressed by

> 家でも勉強できません。図書館でも勉強できません。

But は is drawing more attention to this _exceptional_ fact.

As for

> 東京には、たくさん人がいます。

omitting は would just sound like one's stating a fact about Tokyo giving
absolutely no thought to how Tokyo compares to anywhere else. With は, Tokyo is
being implicitly contrasted with other cities.

Without は, it's a bit like saying

> Tokyo has a population of 37,194,105 people.

OK. Nice fact. You wouldn't think of the population of other cities because,
well, every city has a population. The は, however, is saying, "Tokyo has a lot
of folk [when compared to other cities]".

