There are FOUR conditional tenses in English.
We will start by looking at the ZERO conditional
Structure: IF + PRESENT SIMPLE, … PRESENT SIMPLE
Example: If water reaches 0 degrees, it freezes
If I drink gin, I cry!
We use the zero conditional to describe things that are always true (i.e. there are NO(or zero!) special conditions necessary in order for the second part of the clause to happen.
Think of the zero conditional as FACT or RELIABLE REALITY. As we move towards the FIRST,
Some advanced points for definite and indefinite articles:
Classes (formal): The tiger is threatened with extinction.
To name a work by an artist: My mother found a Salvador Dali in the attic.
National groups: The Irish are known to be great writers and drinkers.
In measurements ‘a/an’ can be used instead of ‘per’: If petrol costs €1 a litre and your car is travelling at 50 miles an hour, how much will it cost to drive for 10 miles?
Some plural political/music/other groups: The government is evenly divided between the