first of all

• Expresión que se usa para introducir el primer punto, paso o motivo de una secuencia, tanto al hablar como al escribir.

A transitional phrase used to introduce the first point, step, or reason in a sequence, often in speech or writing.

1. Sequence markerA2formal

   Used to introduce the first point or step in a series.

   en primer lugar

   • First of all, let me thank everyone for coming.
   • First of all, we need to gather the necessary materials.
   • First of all, I want to clarify the main objective.

2. Emphasis on priorityA2informal

   Used to emphasize that something is the most important or initial consideration.

   En primer lugar

   • First of all, you should apologize for your mistake.
   • First of all, let's make sure everyone is safe.
   • First of all, I need to finish this report.