Can you use the polite form ます with ので?

Question

I was recently told by someone that you cannot use the polite form ～ます and ので; that is, ので must be used with the plain form. (Specifically, he was saying that 「勉強していますので」 was wrong, and had to be changed to 「勉強しているので」.)

That sounded a bit dubious to me when I heard it, since I've seen plenty of sentences which involve ～ます verb and ので. So I went and checked online a bit. The majority of results I found were perfectly okay with using ～ますので, but a couple seemed a bit strange.

• This page downright says "don’t use –masu at the end of the verb", but doesn't explain why.

• I wasn't able to fully read this entry, but it seemed to talk about what I'm asking. Could someone just give a brief summary of what it talks about?

So was the person who told me you can't use ～ますので mistaken, or is there some deeper commotion about this that I'm not aware of?

Answer 1

To answer the title question, I would have to say, "Yes, you can."

If you lived in Japan, you would hear 「ますので」 at least a few times everyday and even more times on some days. We use it whenever we speak rather politely. When do we speak politely? We do so in business, in conversations with teacher/mentor figures, strangers, etc. 「ますので」 is needed because it sounds better than 「ますから」. 「から」, at times, sounds too light and informal to go with 「ます」 and using 「ますので」could solve this problem instantly.

Foreign language learners, however, when they learn that two words have the same meaning, naturally tend to switch them around too freely in what they say or write. They use the two words (in this case, 「から」 and 「ので」) interchangeably without making necessary alterations in the other parts of their speech or writing. This is the reason that 「ますので」 could sound "off" if not incorrect at times if you forget to make everything else on the same politeness level as 「ますので」. This is also what your second link talks about as well. (Forget about your first link as its author clearly does not know enough Japanese.)

「[勉強]{べんきょう}してるから、[電話]{でんわ}しないでね。」 Natural and informal. Just nice.

「勉強してるので、電話しないでね。」 Borderline natural as 「ので」 is a bit too heavy to go with the informal second half.

「勉強していますので、電話しないでね。」 Grammatical but very unnatural.　Polite top and informal bottom.

「勉強していますので、電話はしないようにしていただけますか。」 Natural combo of first and second halves.

Answer 2

[Work in progress; got a bit tired halfway through. Will come back to finish translating in a bit.]

Taken from the entry you linked. Might be a bit loose at some points, but it should get the point across.

Q: A student often uses 「〜ますので」. It's not that he's wrong, but the sound of it together sounds off. What would be a good way to explain this?

He's mixing up styles.

超敬体【ちょうけいたい】 takes the formality up a level from standard polite speech. It comes off as over-polite.

The following example is in standard polite Japanese:

ジャズが好きなので、
疲れて帰ってきたときは、
シャワーを浴びて食事をしたあと、
眠るまで聞いています。

[Loose Translation: "I really like jazz, so I listen to it when I'm tired and coming home, while I'm showering and having dinner, on up until I go to bed."]

This example uses から instead of ので, but keeps it at about the same level:

ジャズが好きですから、
疲れて帰ってきたときは、
シャワーを浴びて食事をしたあと、
眠るまで聞いています。

If you change から in the second example back into ので directly, however, it sounds a bit weird:

ジャズが好きですので
疲れて帰ってきたときは、
シャワーを浴びて食事をしたあと、
眠るまで聞いています。

This sort of change comes off as バカ丁寧, however it's easy to miss why. This next example, using 「〜ますので」 has the same issue.

Proper:

このごろ毎晩、疲れて帰ってくるので、
シャワーを浴びたあと、
オンザロックを飲んでから
軽い食事をして休むことにしています。

["Because I've been tired when I come home every evening recently, I shower and then have a whiskey, after which I have a light meal and get some rest."]

Improper:

このごろ毎晩、疲れて帰ってきますので、
シャワーを浴びましたあと、
オンザロックを飲みましてから
軽い食事をしまして休むことにしております。

With verbs, 「〜ますから」 is considered standard formal:

このごろ毎晩、疲れて帰ってきますから、
軽い食事をして休むことにしています。

["Because I've been tired when I come home every evening recently, I have a light meal and get some rest."]

This 「〜から」, at its root, is connecting sentences. Therefore, in the case of 「Ａ＋から＋Ｂ」, A and B need to be in the same style.

[to be continued]