# Where does negation go with "if" vs "unless"?

1(Q) - Unless he finds a job soon, his family will starve.
1(A) - If he doesn't find a job soon, his family will starve.

2(Q) - Unless she leaves now, she will miss the train.
2(A) - If she leaves now, she will not miss the train.

3(Q) - Unless you hurry, we will leave you behind.
3(A) - If you hurry, we won't leave you behind.

1st answer put negative/not in front of find, not behind will. (Not every time behind modal verb; why is that?)
2nd answer put negative/not behind will, not in front of leave.
3rd answer put negative/not behind will, not in front of hurry.

I want to know where to put not/negative when used in conjunction with if/unless.

• Are these not different structures? 2 and 3 could also be If she doesn't leave now, she will miss the train and If you don't hurry, we will leave you behind; alternatively 1 could be If he finds a job soon, his family will not starve. So there is no difference if the same clause element is negated. Or am I misunderstanding you? Jul 5, 2018 at 14:29
• Where did you get this? I would say the first pattern matches the way most people would say these things most of the time. "If she doesn't leave now, she will miss the train." The third one would more likely be, "You'd better hurry if you don't want us to leave you behind," but I know that doesn't really fit with the purpose here. Jul 5, 2018 at 14:31
• @OliverMason Thanks. I am just referencing the answers from gov exam guide. I want to know the alternative answers of 2/3 from your comment are grammatically corrected . If it was, I am cleared. Thanks. Jul 5, 2018 at 14:34
• The options for 2 & 3 are not logically equivalent.
– AmI
Jul 5, 2018 at 20:13
• Could you provide the sme number of "if" structures, or should eveyone interested guess on the basis of your "unless" examples, please? Jul 5, 2018 at 20:47

The two ways of 'negating' an 'unless' sentence are not equivalent.

The Q & A versions of your first example mean the same thing.

"Unless he finds a job soon, his family will starve."

means that his family will starve if he does not find a job soon. It says nothing about what will happen if he does find a job soon. They may starve, or they may not. You can express that as

"If he doesn't find a job soon, his family will starve."

On the other hand:

Unless she leaves now, she will miss the train.

does NOT mean the same as

If she leaves now, she will not miss the train.

The 'unless' version only says what will happen if she does not leave now. She may still miss the train if she leaves now.

So of your three examples only in number 1 are the Q and A versions equivalent.

If should be said that people with a poor grasp of formal logic (which is lots of people) will use the 'wrong' version.

• Oh, God bless Myanmar Government of Education. Thank you so much. Understand it well. Jul 5, 2018 at 14:42
• Unless means 'if ... not ...', so (1A) is a transform of (1Q). However, not has to stick inside the clause introduced by unless, so (2) and (3) are incorrect. The correct equivalent first clauses would be if she doesn't leave now and if you don't hurry, with no changes in the second clause. Jul 5, 2018 at 23:29
• This answer would be infinitely better if it explained why the second and third examples are wrong. For example, see JL's comment above. Jul 12, 2018 at 22:49