Question

Diminutives are more frequently used than in English. Some words only exist in the diminutive form, e.g. "Kaninchen" ("rabbit") derived from Old French word 'conin', which in turn is from the Latin diminutive cuniculus. 

The diminutive is formed in standard German by adding the suffixes –chen or –lein.

You need to remember three main things about them:

• they always make the noun neuter;
• they never change in the plural; and
• they usually add an umlaut to the base word when they can

Examples:

• das Mädchen
• das Kindchen or das Kindlein (from Kind)
• das Bäumchen or das Bäumlein (from Baum)
• das Kaninchen
• das Hündchen or das Hündlein (from Hund)
• Bach -> Bächlein
• Brot -> Brötchen
• Punkt -> Pünktchen

If the last letter is a vowel, it is often omitted when forming a diminutive:

• Schraube -> Schräubchen
• Katze -> Kätzchen

There's also a separate diminutive "-i/-y" form mainly used with person names:

• Hans -> Hansi
• Fred -> Fredi
• Thomas -> Tommy

 Dialects, particularly Southern ones, offer many further possible suffixes, including "-ke", "-le", "-li", "-l", and "-erl". Nicknames frequently receive an "-i" or "-ie" ("Hansi", "Berti", "Angie").