introductory element
introductory element (elemento introductorio)
a word, phrase or clause that comes before the main clause and is usually followed by a comma.
Example
After lunch, the team went back to work. (After lunch is the introductory element.)
In Spanish
introductory element (elemento introductorio) — una palabra, una frase o una cláusula que va antes de la cláusula principal y que casi siempre lleva una coma después.
After lunch, the team went back to work. (After lunch es el elemento introductorio.)