second conditional

Refiere a una situación hipotética y se forma según la estructura if + simple past + simple condicional. Aquí tienes algunos ejemplos traducidos.

If clause Main clause
If + Past Simple would / could / might + verb
If I won the lottery, I would travel around the world.

Example:
If I won the lottery, I would travel around the world.
If I were in Brazil, I would go to Rio de Janeiro.

first conditional

Se forma con if + simple present + simple future. Se emplea cuando una situación es real o posible: If it rains today, I'll stay at home. Aquí tienes algunos ejemplos traducidos.

If clause Main clause
If + Present tense will / can / may / must + verb
If it rains today, I'll stay at home

Example
If it rains today, I'll stay at home.
If he is busy now, I will come back tomorrow.