Se is an Italian conjunction that translates to 'if' in English. It is used to introduce a conditional clause or a hypothetical situation.
Se piove, non usciremo.
If it rains, we won't go out.
Non so se venga stasera.
I don't know whether he will come tonight.
Sei qui da quando?
Since when have you been here?
Non ho mangiato se non avevo fame.
I didn't eat because I wasn't hungry.
A1: Sei italiano?
Are you Italian?
A1: Non so se posso venire.
I don't know if I can come.
A1: Dimmi se hai bisogno di aiuto.
Tell me if you need help.
B1: Se studi, passerai l'esame.
If you study, you will pass the exam.
B1: Se avessi saputo, sarei venuto anch'io.
If I had known, I would have come too.
B1: Se mi chiamerai, ti risponderò subito.
If you call me, I will answer right away.
C1: Se avessi vinto alla lotteria, avrei comprato una casa al mare.
If I had won the lottery, I would have bought a house by the sea.
C1: Se fossi ricco, viaggerei per il mondo intero.
If I were rich, I would travel around the whole world.
C1: Se non fosse piovuto, saremmo andati in bicicletta.
If it hadn't rained, we would have gone cycling.
In Italian, se is one of the most commonly used conjunctions. It is used to express a condition or a possibility that depends on something else. For example, 'Se piove, non usciamo' means 'If it rains, we won't go out'. In this case, the action of going out is conditioned by the fact that it's not raining.
Se can also be used to express a hypothetical situation or a wish. For instance, 'Se fossi ricco, comprerei una casa al mare' means 'If I were rich, I would buy a house by the sea'. In this case, the speaker is expressing a desire that is unlikely to happen but still possible.
It's important to note that se is always followed by the subjunctive mood in Italian. This means that the verb that follows se will have a different form than usual. For example, 'Se avessi più tempo, leggerei di più' means 'If I had more time, I would read more'. The verb leggere (to read) is conjugated in the subjunctive mood as leggerei.