The general concept behind words like allerlei and keinerlei is that they function as indefinite pronouns or articles to express quantity or quality in a broad, nonspecific way. They can be seen as quantifiers rather than ordinary adjectives and do not adopt typical German declension endings.

banner5 PLACEHOLDER

The word allerlei generally means "all kinds of" or "various," indicating a diverse or wide range of things.

Und hier finden sich allerlei antike Erfindungen.

And here there are all kinds of antique inventions.

Caption 10, Erfinder: Nie erfundene Erfindungen

 Play Caption

Und der Neandertaler entwickelt allerlei Jagdmethoden.

And the Neanderthal develops all sorts of hunting methods.

Caption 34, Es war einmal... der Mensch: Der Neandertaler

 Play Caption

The word vielerlei means "many" or "various," but not necessarily "all."

Welche Bäume liebst du besonders?

Which trees do you especially love?

Caption 63, Deutsch mit Eylin: Bäume

 Play Caption

Ihre Bedeutung zeigt sich in vielerlei Hinsicht.

Their importance is evident in many ways.

Caption 46, Deutsch mit Eylin: Bäume

 Play Caption

Lastly, keinerlei means "no kind of" or "no type of" and is used to emphasize the complete absence of something.

Im Freizeitbereich gibt es keinerlei Vorschriften in Deutschland.

In the leisure sector, there are no regulations whatsoever in Germany.

Caption 55, Cettina erklärt: Sitten und Bräuche

 Play Caption

Es gibt keinerlei Hinweise dafür, dass Flüchtlinge öfter Straftaten begehen als andere Menschen.

There is no proof whatsoever that refugees commit crimes more often than other people.

Captions 42-43, Flüchtlingskrise: 10 Vorurteile, die nicht stimmen

 Play Caption

There are a few more words to know: The word einerlei means all the same, of no consequence, or identical. It is often used to express that something does not matter or is indifferent, for example, Es ist mir einerlei means "It is all the same to me" or "I don't care."

Additionally, the word zweierlei means "two kinds of" or "two types of," and dreierlei can be used in case of three. You will see this, for example, on restaurant menus.

Further Learning
Try using these words in a sentence, or look them up on Yabla German.