In Spanish, when a relative clause follows a preposition (con, en, a, de…), you cannot use que alone. Instead, you must use a relative pronoun with a definite article: el que, la que, los que, las que or el cual, la cual, los cuales, las cuales (more formal) These structures refer back to a noun and show the relationship expressed by the preposition. 🔹 La casa en la que vivo está lejos. = The house in which I live. 🔹 Es la persona con la que trabajo. = The person with whom I work. 🔹 El cine al que vamos está cerrado. = The cinema to which we go. We also use lo que when the reference is not a noun, but an idea or situation: 🔹 No entiendo lo que dices. = I don’t understand what you’re saying.