ZERO CONDITIONAL

Este condicional refiere a una situación que es siempre verdadera (verdades universales): If you freeze water, it turns into ice.

If clause	Main clause
If + Present tense	Present tense
If you freeze water	it turns into ice.

EJERCICIOS

http://www.nspeak.com/newbasic/grammatica/condizionalezero.htm

http://web2.uvcs.uvic.ca/courses/elc/studyzone/330/grammar/0cond1.htm

http://www.my-english.edu.pl/index.php?id=67

http://www.learnenglish-online.com/grammar/tests/zeroconditional.html