When to use arimasu/imasu or desu?

Quote from ashwinr
Minna-san konnichiwa,

I'm a little confused on when to use Desu and when to use arimasu/imasu.

For example if I say:
This is a television => Kore wa terebi desu.

But can I use: kore wa terebi arimasu?

So basically I'm asking if the are interchangeable?

They're not interchangle.

Desu is a coupula which basically means its the equivalent of the "to be" verbs. However desu more insinuates "it is" and so you'd use Desu for the following:

That cat is black. (Sono neko ha kuro desu)
I'm happy. (Ureshii desu)
How are you? (Genki desu ka?)
What's that? (Nan desu ka?)
Who is that? (Dare desu ka?)
Where are we? (Doko desu ka?)
I like cheese. (Chizu ha suki desu.)
I like the color green (Midori ha suki desu.)
etc.

Imasu/Arimasu more state something is in existence. Like:

There is a cat over there. (Soko ni neko ga arimasu)
Who is there? (Dare ga imasu ka?)
There is plenty of cheese. (Ippai chizu ga arimasu.)
Do you have green? (Midori ha arimasu ka?)
Spongebob is here! (Suponjibobu ha imasu yo!)

Also note that Imasu is used only on people/certain animate objects. Arimasu is used only on animals/inanimate objects!... I think Imasu can be used for animals actually... I'm not sure Sayaka may have to clarify that one xD. However NEVER use arimasu with a PERSON as it is a rather harsh statement of "your not human" or "your just a thing" etc. Putting it simply it's not nice.

Quote from Sayaka
Konnichiwa!

This is an excellent and important question.

IMASU vs. ARIMASU

Japanese has two verbs for saying "exist(s)"

When speaking of PEOPLE or ANIMATE THINGS - いる／います (iru/imasu) is used.
When speaking of INANIMATE THINGS and PLANTS - ある／あります (aru/arimasu) is used.

Moreover, these words are used not only to speak of whether someone or something exists, but also to speak of whether something or someone exists in a particular place - "is present/is here/ is there" - or, even to say "I have" or "he/she has" (talking about possession).

For example:
"There is a TV here" or "A TV is here" would be ここにテレビがあります (Koko ni terebi ga arimasu). We use ARIMASU because TV is an INANIMATE thing.

"There is a person here" or "A person is here" would be ここにひとがいます (Koko ni hito ga imasu). We use IMASU because PERSON is an ANIMATE noun.

-SAYAKA

but sometimes , I would think, you can use bith. That the difficulty.

For example when people say I am, they would say:" Watashi wa Ashwin desu"

But as a person I exist, so couldn't you use imasu?? => Watashi Wa Ashwin imasu. I am, therefor I exist!

Or there is a key on the table: "Teburu ni, kagi desu"

Minnasan Konnichiwa!

Let's take the correct phrase:
わたしはアシュウィンです。(Watashi wa Ashwin desu.)
And the incorrect phrase:
わたしはアシュウィンいます。(Watashi wa Ashwin imasu.)

AS Derek-san has mentioned beforehand, です and います are not interchangeable.

It's perhaps better to think of いる and います as the English equivalent of someone "is present/is here/ is there".

For example,
"I am here." would be わたしはここにいます。(Watashi wa koko ni imasu.)
"Ashwin is here." would be アシュウィンはここにいます。 (Ashwin wa koko ni imasu.)
"Derek is there." would be デレックはそこにいます。 (Derek wa soko ni imasu.)

On the other hand, です (desu) is equivalent to "(I) am" or "(he/she/it) is" or "(they) are" in English - it does not suggest that someone is here/there - or is present.
So, if we were to directly translate わたしはアシュウィンいます。(Watashi wa Ashwin imasu.) it would roughly sound like "I am Ashwin is here/there." which is incorrect.

-Sayaka

Quote from Sayaka
Minnasan Konnichiwa!

Let's take the correct phrase:
わたしはアシュウィンです。(Watashi wa Ashwin desu.)
And the incorrect phrase:
わたしはアシュウィンいます。(Watashi wa Ashwin imasu.)

AS Derek-san has mentioned beforehand, です and います are not interchangeable.

It's perhaps better to think of いる and います as the English equivalent of someone "is present/is here/ is there".

For example,
"I am here." would be わたしはここにいます。(Watashi wa koko ni imasu.)
"Ashwin is here." would be アシュウィンはここにいます。 (Ashwin wa koko ni imasu.)
"Derek is there." would be デレックはそこにいます。 (Derek wa soko ni imasu.)

On the other hand, です (desu) is equivalent to "(I) am" or "(he/she/it) is" or "(they) are" in English - it does not suggest that someone is here/there - or is present.
So, if we were to directly translate わたしはアシュウィンいます。(Watashi wa Ashwin imasu.) it would roughly sound like "I am Ashwin is here/there." which is incorrect.

-Sayaka

Thank you, that was very clear.