Comprimento vs. cumprimento
The Portuguese words comprimento and cumprimento are paronyms, meaning they sound very similar but have distinct meanings. This similarity often causes confusion for learners, but their uses are completely different.
Comprimento
A2The word comprimento is a noun that refers to physical length, dimension, or duration. It is used to describe how long something is, either in space or in time.
Qual é o comprimento da ponte Rio-Niterói?
(What is the length of the Rio-Niterói bridge?)
Ela cortou o cabelo, agora tem um comprimento médio.
(She cut her hair, now it has a medium length.)
O comprimento do filme é de duas horas e meia.
(The length of the movie is two and a half hours.)
Precisamos medir o comprimento da parede antes de comprar o sofá.
(We need to measure the length of the wall before buying the sofa.)
O comprimento da saia não é apropriado para a ocasião.
(The length of the skirt is not appropriate for the occasion.)
Cumprimento
B1The word cumprimento is a noun that refers to a greeting, a salutation, or the act of fulfilling, completing, or carrying out a task, duty, promise, or order.
O aperto de mão é um cumprimento formal.
(The handshake is a formal greeting.)
O cumprimento de suas promessas é muito importante para ele.
(The fulfillment of his promises is very important to him.)
Envie meus cumprimentos a todos em sua casa.
(Send my greetings to everyone in your home.)
A empresa exige o cumprimento rigoroso dos prazos.
(The company demands the strict fulfillment of deadlines.)
O soldado agiu em cumprimento de uma ordem direta.
(The soldier acted in fulfillment of a direct order.)
Summary
In summary, use comprimento (with an o) when discussing physical measurement, size, length, or duration. Use cumprimento (with a u) when referring to the action of greeting someone or fulfilling a duty, task, or promise. A simple way to remember is that cOprimento relates to hOw lOng something is, while cUprimento is an action that yoU do.