Learn Spanish (Latin America): El hombre confunde el carro rojo con el mío.

In Spanish, when a possessive word stands alone to replace a noun (acting as a possessive pronoun), it usually needs a definite article (el, la, los, or las) in front of it. Because it replaces "my car" rather than describing it, we use el mío.

How do I know whether to use el mío, la mía, los míos, or las mías?

The pronoun has to match the gender and number of the noun it is replacing, not the person who owns it! Here, "mine" refers to a car (el carro). Since carro is masculine and singular, you use the masculine singular pronoun el mío.

Is con the standard preposition to use with confundir?

Yes, just like in English! When you confuse one thing with another, Spanish uses the formula confundir algo con algo. So, he confuses the red car (el carro rojo) with (con) yours.

Is carro the only word for "car"?

No, but it is very common in many parts of Latin America, like Mexico and Colombia. You will also hear auto (very common in South America) or coche (used in Spain and some Latin American countries). If you used el auto rojo con el mío, the grammar works exactly the same!