I understand the notion of using estar rather than ser when the job is temporary, but there is absolutely nothing in the question to indicate that the job is a temporary or permanent position in most of the examples If a job is to be permanent would you use ser rather than estar when referring to an appointment that someone is going to take up? In the test questions and examples, it would seem not but the lesson notes don't explakin why.
The clear indication in the questions is the presence of the preposition "de" in the sentences right after the verb. If these where talking about permanent jobs (saying what people do for a living) you will have to use "ser" but never "ser de + profession".
Yo soy camarera. (permanent profession)
Yo estoy de camarera. ( temporary job)
Yo soy de camarera. (incorrect)
Yo estoy camarera. (incorrect)
I hope this helps to clarify it.
Sign in to submit your answer
Don't have an account yet? Join today
Test your Spanish to the CEFR standard