"I think Mr. Tanaka will probably come to school."
"Mr.Tanaka" is an adult. Native in japan use "san", when they use polite expression or saying to femal. which is like a "Mr/Ms" in English.
"san"or"chan" is used for girls.
but against boys (under elementary school) is not used almost "san". using "kun" instead of "san" against boys.
It is common sense in Japan.
No, not true. Anyone who isn't considered rude will call some other person さん in Japanese. When I lived in Japan, I heard an elderly woman refer to a newborn baby as 「みほさん」. So no, there is no rule in Japanese on what age you should call someone さん where it sounds odd to call someone younger than you "Mr/Ms" like there is in English.
だ is not needed here. と connects all ending forms and so 来る is already good enough. Adding だ actually makes it wrong. You have seen a lot of instances with だ+と but those are connecting a noun or a Na-type adjective.
田中さんだと思います。/ I think it's Mr. Tanaka.
田中さんはきれいだと思います。/ I think Ms. Tanaka is pretty.
Interesting. I never learnt it but i had always assumed だ was the verb stem of です and that we had to use that stem before と. That would explain why:
- 来ますbecomes 来ると思います ("he will come" -> "I think he will come")
- 田中です becomes田中だと思います ("it's Tanaka" -> "I think it's Tanaka")
But you're saying だ is used to connect nouns and adjectives? Can you expand on this? Do you mean it's some kind of particle?
Thank you for the confirmation. I didn't know the term "ending form". I must have misread your sentence "You have seen a lot of instances with だ+と but those are connecting a noun or a Na-type adjective." then. So if だ is actually a form of です, why would it be restricted to Na-adjectives and nouns? By this I mean why not also i adjectives? You gave the example
- 田中さんはきれいだと思います。/ I think Ms. Tanaka is pretty.
But wouldn't the following sentence also be correct:
- 今日は あついだと思います。/ I think that today is hot
When I say "Ending form" I refer to the term "終止形". We end a sentence with this form.
I think 今日は暑いだと思います is wrong because だ should not have been there. As I understand, 今日は暑い is already a complete sentence, but です can be added arbitrarily to make it more polite. This い＋です formation may actually be awkward. It certainly must not be reduced to い＋だ.
Personally I do not prefer translating 形容動詞 as any term involving "verb". IMHO the 動 character only says this type of adjectives is dynamic, having variations.