ているis doing; is (in a state); does regularly
Something started, and it is still so. That one idea covers "is cooking", "is open" and "walks there every morning".
still going
My younger sister is making dinner in the kitchen now.
still so
The window is open, so the room is cold.
still the routine
I walk to the station every morning.
How to form it
Verb in the て-form + いる
Polite います, negative いない, past いた. In conversation the い usually drops: 食べてる, 見てます.
The idea
ている says that something began before now and is still in effect. What that looks like depends on the verb.
Something you do for a while: 食べる, 読む, 待つ, 降る
It is still going.
It is raining.
A change that happens in a moment: 開く, 結婚する, 死ぬ, 来る
It happened, and the result still holds.
The shop is open.
Either kind, with 毎朝, いつも or 最近
The routine still holds.
I run every morning.
A quick test: can you do it for ten minutes? 10分読む makes sense, so 読んでいる is "is reading". 10分結婚する doesn't, so 結婚している is "is married".
Still going: is doing
The teacher is speaking with a student now.
When I called, my father was washing the car in the yard.
I have been working at this company for three years.
English switches to "have been working". Japanese stays with ている.
Still so: the result of a change
With a verb for a sudden change, ている doesn't mean the change is under way. It has happened, and nothing has undone it.
My older sister is married.
This watch is broken.
Three that catch English speakers
The goldfish is dead.
Not "is dying". For that, say 死にそうだ.
Tanaka is already here.
Not "is coming". He came, and he is still here.
My father is in Osaka now.
Not "is going". He went, and he is still there.
Still the routine: does regularly
My older brother swims at a nearby pool three times a week.
Lately, my older sister has been commuting to work by bicycle every day.
The time word does the work. Take it away and the same verb means right now.
I am running along the river now.
I run along the river every Sunday.
毎朝走ります is fine too. 走っています adds the nuance that this is what you are doing these days.
Words you'll use every day
These are nearly always in ている, and English uses a plain verb for all of them.
"Don't know" is 知らない
知っている is "know", but its negative isn't 知っていない. It goes back to the plain verb.
Sorry, I don't know.
Not said: すみません、
(Sorry, I don't know.)
"Not yet" is まだ〜ていない
To say you haven't done something yet, use まだ with ていない. The past tense doesn't work here.
I haven't eaten lunch yet.
Not said: まだ
(I haven't eaten lunch yet.)
In conversation
In conversation the い usually drops, and it drops from every form: ていた becomes てた, ていない becomes てない, and ています becomes てます. Nothing else changes.
What are you doing now?
Sorry, I was asleep.
I haven't eaten anything yet.
I'm waiting at the station now.
One step further: before の, the る of てる often becomes ん.
What are you doing now?
Check yourself
1What does this mean?
兄は
Choose an answer to see why.
2"I don't know."
Choose an answer to see why.
3"I haven't read it yet."
まだ
Choose an answer to see why.
More detail
When it could be either
着ている can be "is putting on" or "is wearing". It is nearly always "is wearing"; 今、着ているところ makes the other meaning clear.
ている or てある?
The window has been left open.
Someone opened it for a reason.
More sentences
A cat is sleeping on the sofa.
It was not raining at that time.
The light is on, so someone is still there.
The shop was closed in the morning.
My mother bakes bread every Friday.