なので relationship does not seem to match in そうじが楽なので、部屋にはなるべく物を置かないようにしている

Question

This is one of the questions taken from the book 「N3文法スペードマスター」:

そうじが楽（　）、部屋にはなるべく物を置かないようにしている。

The blank in the bracket is to be filled with one from this set of choices: はず、のに、ため、ところ、べき、なので

I'm not too sure if I'm right or not, but I translated the second half of the sentence as this: I make it a point to, as much as possible, not leave stuff lying around in the room.

After translating that, I proceeded to translate the first half as: cleaning is easy ( ), . From there, I thought of there being a relationship between the two halves as such: In order for cleaning to be easy, I make it a point to, as much as possible, not leave stuff lying around in the room.

However, I cannot find any answer from the set of choices that could possibly fit that description, and the answer from the book was なので, which, as I would translate it, makes the sentence something like: Because cleaning is easy, I make it a point to, as much as possible, not leave stuff lying around in the room. (Edit: I chose ため as my answer. I kind of forgot that that answer seemed logical to me before I checked the book's answer and got confused.)

That didn't really seem logical to me, and after pondering for awhile, I reasoned the answer as: I make it a point to, as much as possible, not leave stuff lying around in the room, because cleaning will be easy then.

However, that brings up another question, which is how the discrepancy cleaning will be easy instead of cleaning is easy came about. Perhaps my translation of そうじが楽 is wrong?

Thanks in advance! Hope my question is clear enough and doesn't sound lame.

Answer 1

Ignore the meaning of the sentence; it is secondary to grammar. Firstly, evaluate which options can grammatically be inserted. Lets check each one.

• -hazu can attach directly to an adjective or verb, to adjectival verb + na, and to noun + no. raku is either a noun or adjectival verb so needs to be raku na/no hazu, so you can eliminate this as an option.

• -noni directly attaches to adjectives and verbs but requires na before nouns. Again, this cannot fit so you can eliminate it.

• -tame requires no when attaching to nouns, na when attaching to adjectival verbs, and can attach directly to adjectives and verbs. This does not fit, so you can cross it off the list.

• -tokoro requiers no when attaching to nouns and can attach direclty to verbs. This will not work, so eliminate it.

• -beki requires dearu when attaching to nouns and adjectival verbs, -ku aru for adjectives, and directly to verbs. No luck here, so remove it.

• -nanode: Rather, you should think of this as -node, which attached directly to adjectives and verbs, but requires na when attaching to nouns and adjectival nouns. This fits, which is good because we have already eliminated all of the other options.

Here the meaning is not important. It is only a matter of grammar. When there are multiple valid choices, then the intended meaning becomes more important.

Answer 2

I think the only grammatical choice is なので, which has the copula な to be modify ので.

楽 by itself can't modify any of the other choices. If you go by meaning, then 楽なため does make sense, but it's not an option. Similarly, 楽なはず or 楽なのに are not even an option.