Matching Pairs zero conditionalOnline version The zero conditional is often used to refer to general truths. The tense in both parts of the sentence is the simple present. by Silvia Yumbillo 1 If water reaches 100ºC, 2 If you feel sick, 3 If you don't put sun cream on, 4 If you heat ice, 5 If my dog sees the postman go to the doctor It barks. it boils. you get burnt. it melts