School
Often refers to K-12 school, especially private schools or high schools in many regions.
Commonly used for 'high school' or a technical/vocational institute.
Used for 'high school' in several South American countries like Chile and Venezuela.
Specifically for 'university' or 'college' (higher education). Not for K-12.
The children go to school in the morning.
Is your son in a public or private school?
My older sister studies at the university.
The school is near my house.
'Escuela' is the most general, universally understood term. 'Colegio' is also very common but can specifically refer to private K-12 schools or high schools, depending on the country.
'Colegio' (or 'el cole') is the standard word for primary/middle school. 'Instituto' is used for high school. 'Escuela' is less common for general schooling and often refers to specialized schools (e.g., 'escuela de idiomas').
'Escuela' is the standard term for all K-12 levels (primaria, secundaria). 'Colegio' strongly implies a private school.
'Colegio' is the most common term for both primary and secondary school, public or private. Using 'escuela' can sometimes imply a rural or very basic primary school.
'Escuela' is common for primary school, while 'colegio' is often used for secondary school ('colegio secundario').
'Colegio' is a common term for K-12 schools. 'Liceo' is specifically used for public high schools.
Using 'colegio' to mean 'college' (university). — This is a very common false friend. 'Colegio' in Spanish refers to K-12 school, not higher education. To talk about university, you must use 'universidad'. Incorrect: 'Estudio en el colegio.' (if you mean university). Correct: 'Estudio en la universidad.'
Not knowing the regional differences. — While 'escuela' is always understood, using the locally preferred term sounds more natural. For example, calling a high school an 'escuela' in Spain would sound strange, as 'instituto' is the correct term.
Mispronouncing 'escuela'. — English speakers often forget to pronounce the 'ue' as a single, quick diphthong ('WEH'). They might say 'es-coo-EH-la' instead of the correct 'ess-KWEH-lah'.