First Conditional

FIRST CONDITIONAL

The structure of the first conditional

If + sujeto + present simple, sujeto + future simple

For the phrase of the future we mostly use the simple future with will, but we can also use the simple future with going to or a modal verb: can, might, should, or must.

• WILL: If the weather is nice on Sunday, we'll go on a picnic.
• GOING TO: If I don't have to go to work tomorrow, I am going to visit my parents.
• CAN: If the meeting finishes early, we can go for a drink. 
• MIGHT:If I have time this afternoon, I might wash my car.
• SHOULD: If they invite you, you should go.
• MUST: If you have any problems, you must call me.    

How is the first conditional used?

The first conditional is used to express future plans, threats, warnings, promises or to convince someone about something.

https://course.lewolang.com/upload/imatges/grammar/a2/25-03-es.jpg

If the weather is fine tomorrow, we will go cycling.