Half a second to choose supe or sabía, and the call has already moved on.

In all of them you are choosing tense and register while the other side keeps talking.

• A supplier call to Mexico

  Nearshored manufacturing runs on calls where nobody switches to English for your benefit. You have to query a delivery date, push back on a price and close with an agreed action, on a line that gives you the audio and nothing else.

• Competency questions, all in the past

  Interview questions arrive in the past tense, which means preterite and imperfect for the whole of your answer: what the situation was, what you did, what happened afterwards. Get the aspect wrong and a finished project sounds like an unfinished one.

• Defending a TFM or thesis

  A Spanish or Latin American master's and doctorate end in an oral defence before a tribunal whose members take turns on your method. You present, then answer their challenges — subjunctive throughout, because it is all what might have been done otherwise.

• Usted, tú or vos

  Register is not decoration. A Bogotá client may use usted with people they know well, an Argentine colleague will say vos tenés, and a Madrid office uses tú where a Mexican one would not. The wrong choice is heard before the grammar is.

• A history taken in Spanish

  In much of the United States, Spanish is simply what the patient in front of you speaks. Taking a history means asking about symptoms, duration and medication, then understanding an answer given fast by someone who is unwell and worried.

• A seminar you have to join

  A semester in Salamanca or Buenos Aires is not lectures alone. You have to interrupt, disagree politely and ask a question in front of thirty people, all of whom speak faster than the reading list prepared you for.

These six are the first to go when the pace rises.

At work nobody tells you which structure was wrong; they answer a slightly different question from the one you meant to ask. Here you find out which clause did that, and the same structure is waiting for you in the next session.

• Reporting the past accurately: preterite for what you did, imperfect for what the situation was, held steady across a long answer.
• Si tuviéramos más tiempo, podríamos — two verb forms that have to arrive in the right order, and the order is what makes a refusal sound considered.
• Vos tenés in Buenos Aires, usted with a Bogotá client you have known for years, tú in Madrid — decided in the first three words and held for the whole call.
• Object pronouns at speed: se lo mando, te lo confirmo, the shortcuts colleagues use instead of naming the thing again.
• Mil against millón, and a date said as one run of syllables — the errors here end up on an invoice rather than in a note.
• ¿Me lo repites? and ¿en qué sentido?, deployed at the first missed word rather than after three sentences of guessing.

Outside our remit

None of this puts your name on a contract, a hospital rota or a master's list, and it does not know a balance sheet from a biopsy — your field's Spanish you look up yourself and bring with you. What gets drilled here is the producing: the same tense, the same refusal, the same figure, until they arrive without assembly.