Here are some examples:
- Léo est gentil, mais il est comme son frère, un peu trop bavard !
- Léo est gentil, mais c’est comme son frère, il est un peu trop bavard !
- Le vent, c’est comme l’amour, ça va, ça vient.
- Ce vent, il est comme celui qu’il y a dans le sud.
- Les chats, c’est vraiment comme les chiens, mais en plus intelligent.
- Le chat est vraiment mignon, il est comme celui qu’on avait vu chez ton cousin.
- Les oiseaux, c’est comme la liberté, ça s’envole à sa guise.
- Tes oiseaux, ils sont comme les miens, vraiment super beaux.
- Cette chaise, elle est comme l’autre, mais en plus abîmée.
- Les chaises, c’est comme des fauteuils, en moins voluptueux.
Sooooo...! There might be a LOT of exceptions and actually, no real rule that works all the time, but I’ll try to explain what happened here:
1. Léo: Only choice possible in both cases. Look at where I placed il and try to figure out a rule of your own with that (because I really don’t know how to explain the difference) 😅
2. Le vent: Only choice possible, but here, it’s a bit easier to explain. The first one is very general, it’s almost like a saying, you know, you don’t talk about a specific wind, you just talk about the idea of the wind, if that makes sense. In the second sentence, you talk about a very specific wind, that’s why you would use Ce vent, and so you compare it with another wind that’s in the South of France, using il est comme.
3. Le chat: Only choice possible in the first sentence if you think of les chats as a general entity, not thinking about any specific cat at all. You could however use les chats, ils sont vraiment comme les chiens, mais en plus intelligent, if you talked about cats as a more specific group of animals... I know, it might be hard to understand... But let’s say c’est comme is more common, here. However, in the second sentence, il est comme is really the one and only possibility, as you talk about a specific cat that you can see. You could even replace Le chat with Ce chat.
4. Les oiseaux: For the first one, no other choice, as it’s just like the first sentence comparing the wind to love, here, it’s almost like a saying, it’s very generic, we don’t talk about any specific birds, it’s just the idea of birds. For the second one, again, I used ils sont comme, because I talk about specific birds, but just as the first pair of sentences, with Léo, I could say: Tes oiseaux, c’est comme les miens, ils sont vraiment super beaux. I guess it would also be a bit more informal, as a way of speaking.
5. Les chaises: Only choice possible in both sentences because it’s, once more, the idea of something specific or not.