1. Comparative Adjectives 

Comparisons in German (der Komparativ) are similar to those found in English. In both languages, the comparative ending ‘er’ is added to adjectives to make them comparative; however, English uses “more” for some adjectives whereas German does not. 

Example: 
Er fährt schnell, aber sie fährt schneller.    
He drives fast, but she drives faster.

In the example, ‘schnell’ is an adjective that simply adds ‘er’ to the end to form the comparative. In German, there are a few rules to be aware of when forming the comparative:

• Monosyllabic adjectives with stem vowel ‘a,’ ‘o,’ or ‘u’ add an umlaut to the stem vowel (e.g. alt → älter; groß → größer; kurz → kürzer)
• Adjectives ending in ‘e,’ ‘el,’ or ‘er’ either add an ‘r’ only or delete the final ‘e’ before adding ‘er’ (e.g. teuer → teurer)

2. “als” and “so… wie“

When we compare two nouns and want to express than one noun is more of something  than another noun (for example, faster, bigger, etc) than another, we use “als” 

Example:
Dein Auto ist schneller als mein Auto. 
Your car is faster than my car. 

When we compare two nouns and want to express that one noun is as much of something as another noun (as fast as, as big as), wie use “so… wie”. In English and in German, we then use the positive/regular adjective, and not the comparative adjective. (“as fast as”, not “as faster as”) If we want to add that something is exactly the same, we can add “genau”. To negate it (“not as fast as”), we can add “nicht”. (nicht so schnell wie). When we use “als” or “so…wie”, the noun is typically in the nominative case. 

Example:
Dein Auto ist (genau) so schnell wie mein Auto. 
Your car is (exactly) as fast as my car. 

3. Irregular Adjectives 

In English and in German, there are adjectives that do not follow the regular comparative pattern of adding “-er”. For example, the comparative of “good” is not “gooder” but “better”. A few examples of irregular adjectives in German are:

gern (gladly)  – lieber (more gladly)
gut (good)  – besser (better)
hoch (high/tall) – höher (higher/taller)
viel (much, a lot) – mehr (more)