Durante vs. mientras
The Spanish words durante and mientras both relate to time and can be translated as during or while. However, they are not interchangeable because they function differently in a sentence. The key difference lies in what follows each word: durante is a preposition followed by a noun, while mientras is a conjunction that connects two actions.
Durante
A2Durante is a preposition that means during or for (a period of time). It is always followed by a noun or a noun phrase and specifies the time frame in which an action takes place. It answers the question "When?" or "For how long?".
El niño durmió durante todo el vuelo.
(The child slept during the entire flight.)
Hablamos por teléfono durante dos horas.
(We talked on the phone for two hours.)
Está prohibido usar el móvil durante la clase.
(It is forbidden to use your phone during the class.)
Durante el verano, viajamos a la playa.
(During the summer, we travel to the beach.)
Aprendí mucho durante mi estancia en Argentina.
(I learned a lot during my stay in Argentina.)
Hubo mucho silencio durante la ceremonia.
(There was a lot of silence during the ceremony.)
Mientras
B1Mientras is a conjunction that means while or as long as. It is used to connect two clauses (two separate actions), indicating that they are happening simultaneously. Because it connects clauses, it must be followed by a conjugated verb.
Yo cocino la cena mientras tú pones la mesa.
(I'll cook dinner while you set the table.)
A ella le gusta escuchar música mientras corre.
(She likes to listen to music while she runs.)
El teléfono sonó mientras me duchaba.
(The phone rang while I was taking a shower.)
Mientras esperábamos, leímos una revista.
(While we were waiting, we read a magazine.)
Puedes usar mi coche mientras yo esté de vacaciones.
(You can use my car while I am on vacation.)
No me molestes mientras trabajo.
(Don't bother me while I am working.)
Summary
In short, the main difference is grammatical. Use durante before a noun or noun phrase (e.g., durante la película / during the movie) to state *when* an action happens. Use mientras before a conjugated verb (e.g., mientras comemos / while we eat) to link two actions happening at the same time.