Questions & Answers about Expresó su deseo claramente.
The accent mark in expresó shows where the stress goes: ex-pre-SÓ.
It also helps distinguish this past-tense form from expreso, which without the accent can mean I express or can also be a noun/adjective in other contexts, such as espresso or express.
So the accent is both a pronunciation guide and a grammatical marker.
It is the preterite tense, which is used for a completed action in the past.
So Expresó su deseo claramente presents the expressing as a finished event: the person clearly expressed that desire at some point in the past.
A learner might compare it with the imperfect:
- Expresaba su deseo claramente = he/she was expressing or used to express his/her desire clearly
The preterite here sounds like a single complete action.