Expressing Obligations, with
~なければいけない
You have to ...
The ~なければいけない (or, more formally, ~なければいけません) structure is one that needs to be learnt as a chunk. It simply means " you have to ..."
A note to help you make sense of this useful phrase:
- It's made up of two parts: ~なければ ("if you don't ~") plus いけない/いけません (it's no good/it won't do)
- It's generally used to talk about general rules, or about what others must do.
- Compare with ~なければならない (I have to...)
An example to whet your appetite:
Forming the structure:
To form the first half (the ~なければ bit):
- Begin with a verb in the plain form negative. E.g. しない (I don't do); やらない (I don't do); 行かない (I don't go)
- Remove the final い and replace with ければ
- So しない becomes しな+ければ (if + I don't do); やらない becomes やらな+ければ (if + I don't do); 行かない becomes 行かな+ければ (if + I don't go). (Obviously, you don't need the plus sign in between...)
To form the second half (the いけない or いけません bit).
- Simply add いけない or いけません, depending on the level of formality you want.
- Which gives you しなければいけません・やらなければいけません (both mean "you have to do"); 行かなければいけません ("You have to go")
Another example: