"Vennen min har sendt meg flere postkort fra Hellas."

Translation: My friend has sent me several postcards from Greece.

[DjypForest]

Why in this case is "a lot of" not accepted to translate "flere"

[Luke_5.1991]

Flere = more, several

Mange = many, a lot of

[MariaNehmeh]

Is the noun after flere always without "er"? And what about other thingies such as "mange"?

[geirda]

The noun is always in plural after "flere" and "mange". In this case "postkort" is plural, since the indefinite singular and plural forms are identical for this word