Often people write model classes with a plural name. For example:

from django.db import models

class Cars(models.Model):
    name = models.CharField(max_length=128)
    brand = models.ForeignKey(Brand, on_delete=models.CASCADE)

Why is it a problem?

Django defines some meta data based on the name of the class. For example the verbose_name ^[Django-doc] and the verbose_name_plural ^[Django-doc] are automatically defined if you do not specify these. That thus means that if we inspect the verbose_name_plural, we see:

>>> Cars._meta.verbose_name_plural
'carss'

Django uses this name for example in the admin page. Some Django packages also use the .verbose_name and .verbose_name_plural information to show dialogs in forms, templates, etc. This will result in grammatically incorrect phrases, and incorrect plural nouns.

It also makes queries look grammatically incorrect English, for example, one queries with:

Cars.objects.all()

Which can be translated as:

All the cars objects.

The objects are already plural, so it makes no sense to make cars plural as well.

For related models, this results in ugly looking names as well, for example one queries with:

ford.cars_set.all()

which again is less elegant compared to car_set.

What can be done to resolve the problem?

You give the class of the model a singular name, so Car instead of Cars:

from django.db import models

class Car(models.Model):
    name = models.CharField(max_length=128)
    brand = models.ForeignKey(Brand, on_delete=models.CASCADE)

An alternative could be to specify both the verbose_name and the verbose_name_plural, but even then it is likely that there is some Django tooling, or Django packages that make use of the name of the model, and thus somehow, it still does not look correct.

Extra tips

Sometimes people name the model after the table name in a database that already exists. You can make use of the db_table option ^[Django-doc] to specify the name of database table, and thus still give your model class a singular name.