What is the difference between だ and ある/いる?
I know だ is the state-of-being word and that ある/いる means to exist (inanimate/animate, respectively), but I'm a little confused as to what situations you would use one choice over the other. If someone could give examples of when you should use each term that would be awesome!

Question

What is the difference between だ and ある/いる?
I know だ is the state-of-being word and that ある/いる means to exist (inanimate/animate, respectively), but I'm a little confused as to what situations you would use one choice over the other.  If someone could give examples of when you should use each term that would be awesome!

Answer

「ある」inanimate objects locate somewhere
　　彼の家がある。
　　いいレストランがある。
　　信号がある。
「いる」animate beings exist somewhere
        兄弟がいる。(I have brothers)
　　私は学校にいる。
　　外に猫がいる。
「〜だ」represent attributes (only with noun / na-adjective)
       私は学生だ。
　　空はきれいだ。
　　AとBは友達だ。
　　図書館は静かだ。
　　これは私のペンだ。

Answer

Mameは猫だ。Mame is my cat.
Mame はいい猫だ。Mame is a good cat.
Mameはきれいだ。Mame is clean.
Mame はここにいる。Mame is here.
Mameの水はそとにある。Mame's water is outside.

Answer

[ある]
His house is located within 10 minutes from a big bridge . 彼の家は、大きな橋から10分以内の場所にある。

[いる]
私は、彼から十分離れた場所にいる。
I am far enough away from him.

[だ]
彼は老衰で死んだ。
He died of old age.
自転車に乗っていてバランスを失い、転んだ。
I lost my balance riding my bike and fell.

Hope this helps.

Answer

Thanks so much, this clears up a good bit.  The more I studied I realized that aru/iru deal with the location of existence.