です and だ

[SGenier]

Hello,

I have heard that it is possible to replace です with だ in informal situation and I was wondering was is the difference between だ and simply omitting です.
For example, are these two phrases interchangable ?
私はサイモン。
私はサイモンだ。

Sorry if this question has already been addressed in the podcast, as I have only listened up to lesson 19. If this is the case, I would appreciate if anyone pointed me to the podcast in question.

有難う in advance.

[kinoko]

they all mean the same thing, but there's just a different nuance. da makes everything seem a bit more emphatic and assertive, and thus sort of manlier or rougher. but i hear girls say da all the time, too, so it's not restricted to males like zo or ze.

[SGenier]

有難うございます、　kinokoさん。

[kinoko]

どういたしまして!　

i recommend you read http://guidetojapanese.org/copula.html. it goes really in-depth.

[SGenier]

Great website.

I just have one question regarding い-adjectives. It is written that you should use だ only with nouns and な-adjectives and never with い-adjectives. But in begginer lesson 4, Peterさん, Kazunoriさん and Natsukoさん are saying
貴方は面白いです。
whitch contains the い-adjective 面白い followed by です.
I guess then that です can be used with these adjectives, but not だ. Is it correct ?
And are there more important differences between the two words ?

[kinoko]

yes, you're correct (and you cant say ~nai da either)... i believe that IS covered on that site, though, and tae kim explains better than i can. tae kim believes that desu and da aren't actually the same words in different politeness levels, though, and i remember him using this in his explanations as to why you don't use da with i-adjectives. but others say that's not true...

i'm not fluent... so maybe someone else could help us out here...

[Charles]

It's helpful if you do not think of です and だ as interchangeable because they're really not.

You cannot use だ to ask a question like you can with desu. Likewise, you cannot use constructions that would follow か, like かも知れない. You also cannot use it before words that express appearances, like 見たい or らしい.

You'll notice that most of the things you can't say with だ are things you would want to say if you are uncertain or speaking about the existence of something in the future.

[Bueller_007]

You cannot use だ to ask a question like you can with desu.

I assume you mean that you cannot use it in the same manner as "desu". But you can, in fact, use it to ask a question. It's all about intonation with "da". Intonation goes up, and it's a question.

For example:
「何だ？」is a valid question used all the time by guys. (Pronounced "Nan da".) It also becomes「何だっけ？」when you're trying to remember something.

And you can optionally use it in combination with the informal question particle「い」(assuming you're a guy).
あんた、何を見てるんだい？("What are you looking at?")