To Exist
“Don’t part with your illusions. When they are gone, you may still exist, but you have ceased to live.” – Mark Twain
ある mostly had to do with having something. いる (or います in ます form) has to do with existing.
いる is all about living, moving things. Things like dogs, people, and of course kittens (da’aww). There are exceptions to this, however. Some non-moving living things get the ある treatment. For example, a tree would use ある instead of いる because trees don’t really move (even though they’re alive). You can have a tree.
correct: 木がある
incorrect: 木がいる。
You do want to use いる when it comes to living, moving things though. What kinds of things are moving and living? Let’s take a look at some examples.
a ともだち が いる。
(I) have a friend. / A friend exists.
a お兄さん が いる。
(I) have an older brother.
a ねこ が いる。
(I) have a cat. / A cat exists (for example, if you see a cat you can say this!)
So, what do you have? Anything living nearby? What kinds of family? Friends? Use the patterns above to name off some things you have (that are living and moving … not trees or plants though!).
Just like ある, you can use いる to indicate where something exists, too.
a いえ には 子犬 が いる。
At home (I) have a puppy.
a マクドナルド に いる。
(Someone’s) at McDonalds.
a ボビーさん は ハーバードだいがく に いる。
Bobby is at Harvard (lit. Bobby exists at Harvard).
Can you see some of the overlap with “existing” and “having” now? いる is more “exists” heavy compared to ある, but ある is more “to have” heavy than いる. Still, they both share some meaning and the main differentiation is what they can be used on (living/moving versus non-living/non-moving).
I’m sure you understand the differences now alright, but I bet it will be even better when we look at both of them together, side by side.