Používání "Unless"

Unless znamená totéž co if...not. Z gramatického hlediska po něm stejně jako po if následuje přítomný, minulý či předminulý čas (tj. nikdy ne podmiňovací způsob). Unless se místo if...not používá ve všech typech kondicionálů. Na pořadí vět v souvětí nezáleží.

Kondicionál 1. typu: Unless + přítomný čas
Věta s "if" Ekvivalent s "unless"
You will be sick if you don't stop eating. You'll be sick unless you stop eating.
I won't pay if you don't provide the goods immediately. I won't pay unless you provide the goods immediately.
If you don't study dilligently, you'll never understand trigonometry. Unless you study dilligently, you'll never understand trigonometry.
Kondicionál 2. typu: unless + minulý čas
Věta s "if" Ekvivalent s "unless"
If he wasn't very ill, he would be at work. Unless he was very ill, he would be at work.
I wouldn't eat that food if I wasn't really hungry. I wouldn't eat that food unless I was really hungry.
She would be here by now if she wasn't stuck in traffic. She would be here by now unless she was stuck in traffic.
Type 3 conditional: unless + předminulý čas
Věta s "if" Ekvivalent s "unless"
Our director would not have signed the contract if she hadn't had a lawyer present. Our director would not have signed the contract unless she had had a lawyer present.
I wouldn't have phoned him if you hadn't suggested it. I wouldn't have phoned him unless you'd suggested it.
They would have shot her if she hadn't given them the money. They would have shot her unless she'd given them the money.