The translation suyo reflects the gender and number of the noun it is standing for; theirs is translated by el suyo, la suya, los suyos, las suyas, depending on what is being referred to.
Here is a selection of useful words and phrases you will need in real-life situations while you're visiting Spain and other Spanish-speaking countries...
Did you know that the primary meaning of almuerzo is lunch? It is used only in this sense in most of Latin America. In Spain and Mexico, where comida is the usual word for lunch, almuerzo can also be a mid-morning snack.