しか～ないonly; nothing but
しか is "only", and the verb after it is always negative: nothing except this, no more than this. With an amount it usually means less than you wanted.
nothing else
In the morning, I only drink coffee.
too few
We needed ten people for the meeting, but only three came.
How to form it
Noun or amount + しか + negative verb
The verb is negative every time: ません, ない, なかった, and "can't" forms like 使えない. しか takes the place of は, が and を.
With other particles
Noun + に／で／と／から + しか + negative verb
These normally stay, in front of しか: にしか, でしか, としか, からしか.
The verb is negative, the meaning is "only"
Take しか as "nothing except". コーヒーしか飲みません is "I drink nothing except coffee", so "I only drink coffee". English keeps its verb positive, which is where the slip comes from.
I can only speak a little Japanese.
English "can only" is しか with "can't".
There are only two apples left.
Not said: 朝は
(In the morning, I only drink coffee.)
With a positive verb, "only" is だけ: コーヒーだけ飲みます.
しか or だけ?
Both are "only". だけ states the limit: this is what there is. しか says there is nothing more, so it often sounds like too few.
I have just one thousand yen in my wallet.
What you have. It may be all you need.
I only have one thousand yen in my wallet.
The same money, said by someone who needs more.
With だけ, a negative verb stays negative. These two say opposite things.
Only Ms. Tanaka came to the meeting.
Nobody but Tanaka came.
Only Ms. Tanaka didn't come to the meeting.
Everybody but Tanaka came.
After a number: fewer than you hoped
しか measures the number against what you needed or expected. It doesn't have to be a small one: six thousand people are too few when you hoped for ten thousand.
We need a week to get ready, but there are only two days left.
The report has to be five pages, and I've only managed to write two so far.
We were aiming for ten thousand people, but only six thousand came.
With に, で, と and から
しか comes after the particle: でしか, never しかで.
You can only buy tickets at the station ticket window.
Mr. Sato is the only person I can ask to do this job.
Not always a complaint
A rule or a plain fact has no disappointment in it. しか just shuts out everything else.
This video can only be watched in the classroom.
All you can see from here is the sea.
Close neighbours
三十人もN4
After a number, も is the opposite feeling: that many is a lot.
It's only a small shop, but thirty people were lined up before it even opened.
After a verb in the dictionary form, しかない is "have no choice but to".
The trains aren't running, so we'll just have to walk.
Check yourself
1Which one fits?
冷蔵庫には
Choose an answer to see why.
2What does this mean?
答えは
Choose an answer to see why.
3Which one fits?
この
Choose an answer to see why.
More detail
だけしか is the two together, with the same negative verb. It presses the point harder: 千円だけしかない, "a thousand yen is all I have".
More sentences
I drank nothing but water last night.
There was only bread for lunch today.
We need six eggs to make cake for six people, but we only have two.
The repair will cost fifty thousand yen, and I only have ten thousand right now.
I will only hand this key over to the building manager.
This dog will only play with me.
Authorized personnel can only come in through the service entrance.