To link ideas in Italian, you can use the word 'che', which works like 'who', 'which', or 'that' in English. It's very versatile. First, let's see how 'che' can be the subject of the clause it introduces. For example, 'Conosco una ragazza che lavora in farmacia' means 'I know a girl who works in a pharmacy'. Here, 'che' refers to 'una ragazza', and she is the one who 'lavora'.

The word 'che' can also act as the object in the clause it introduces. The meaning is the same – 'who', 'which', or 'that'. For example, in 'Il film che ho visto era divertente', 'che' refers to 'il film'. The film is the object; it's the thing that 'I saw'. The subject of 'ho visto' is 'io', or 'I'.