Introduction : conditional sentences talk about a condition ( usually started by if ) and a possible result or consequence.
The if- clause can be before or after the result clause.We use a comma between clauses when the if – clause comes first.Either clause can be positive and negative.
If + present tense , + present tense : if she wroks hard,she saves some money.
Present tense + if + present tense : she saves money if she works hard.
- We use the zero conditional to talk about something that is a general truth or fact ( if has a similar meaning to everytime ) :
If you own a car,you also have to pay for insurance and registration every year.
- It is no longer a fact we use the past tense :
When I was a child,if i helped my mother at home,she gave me extra pocket money.