The conjunctions 자 and 자마자.

Today I’m going to try and explain the conjunctions 자 and 자마자.  These are sometimes translated as “after”, “right after”, and “as soon as”.  One important thing to remember here is that they connect two clauses — one which happens after the other.  But, unlike the patterns -고, -어서, and -고 나서, the patterns 자 and 자마자 connect actions that occur much more closely to one another in time.  Or, put another way, the temporal distance between the two clauses is much smaller.  Hence the translations “right after”, “as soon as”.

For example:
앉고 잠들었어요.  I sat down and fell asleep.  (Maybe you fell asleep 5 seconds after sitting down, or maybe it was 5 hours.)
않자마자 잠들었어요.  As soon as I sat down I fell asleep.  (Closer to 5 seconds or 5 minutes after sitting down; not 5 hours.)

The good part about these two patterns is that they are simple to create.  You simply add 자 or 자마자 to the verb stem.  That’s it.

The bad part is that these patterns do not mean exactly the same thing.  I’ve seen a few Korean textbooks that will tell you they are the same pattern, as if 자 is merely a shortened, more colloquial version of 자마자.   I’m sorry, but this isn’t true.

So here’s what you have to remember:

Vst + 자마자

• Connects two actions temporally (i.e. in time).  One happens right after the other.
• There is no tense marking on the first clause (i.e. the part before 자마자).
• The subject of the first and second clause are almost always the same.
• Does not imply that one action resulted in the other.
• More common in colloquial speech than -자.
• The tense on the final clause (i.e. the end of the sentence) can be in the past, present or future.

Vst + 자

• Connects two actions temporally (just like -자마자)
• There is no tense marking on the first clause (just like -자마자)
• The action in the second clause must be the result of the action in the first clause.  The first clause is the condition or reason that makes the second clause possible.
• 자 is not as colloquial sounding as 자마자.
• The tense in the final clause can only be in the past tense.

Given what I’ve told you above, you should also be able to figure out the following:
You can always replace -자 with -자마자.  However, you cannot always replace -자마자 with -자.

How about a few examples, then, to wrap this all up.

창문을 열자 바람이 들어왔어요.
As soon as I opened the window the breeze came in.  (Here, 자 indicates that the first action — opening the window — directly led to the second action — the wind coming in.  The second clause is a result of the first clause.  You could replace 자 with 자마자, and it would still be grammatically correct.)

한국에 오자마자 한국어를 공부하기 시작했어요.
I started studying Korean as soon as I came to Korea.  (The second clause is not the result of the first clause.  Although they happened one after the other, neither was the result of the other.)

의자에 앉자 잠들었어요.
As soon as I sat down I fell asleep.  (Implies that you fell asleep because you sat down, or that the sitting down was the condition that made falling asleep possible.)

아침에 일어나자마자 식사 준비했어요.
Right after I woke up in the morning I prepared a meal.  (These actions merely happened one after the other.  No causal relationship exists between the to clauses.)