Learn Italian: Il bidone rosso, lo usiamo per il vetro. - The red bin, we use it for the glass.

This is called left dislocation. In spoken Italian, when you move the object (il bidone rosso) to the beginning of the sentence to emphasize it as the topic, you must use a pronoun to refer back to it before the verb. Since bidone is a masculine singular noun, we use the pronoun lo.

Is it grammatically wrong to just say Usiamo il bidone rosso per il vetro?

Not at all! That is the standard, neutral word order. However, bringing il bidone rosso to the front shifts the focus. It is like saying 'As for the red bin, we use it for glass.' This structure is incredibly common in everyday Italian, especially when sorting or contrasting things like recycling.

Does il vetro mean 'the glass' like a drinking glass?

Here, il vetro refers to the material 'glass' in the context of recycling. If you were talking about a drinking glass, you would use the word il bicchiere. Notice that Italians use the definite article (il) for general categories and materials, which is why it is per il vetro instead of just per vetro.

How would the pronoun change if we were talking about the green bins (i bidoni verdi)?