first of all
First of all (adverb) means Before anything else; used to introduce the first item in a list of points, steps or objections. Example: “First of all, preheat the oven to 180°C.”
How to use first of all
Learner’s notesIn plain EnglishThe thing to say or do before all the others.
Neutral to informal. In speech it often signals mild indignation before a rebuttal ("First of all, how dare you"). Formal writing prefers firstly or first.
Follow it with a comma, and if you open a list with first of all, keep the sequence going with second, then, next and finally.
Fill the gap
Can you complete this real example?
_____, preheat the oven to 180°C.