German ß vs ss: When to use Eszett (simple rules)

The German letter ß (called Eszett or scharfes S) often confuses learners. It looks unusual, sounds like “ss” and sometimes seems completely unnecessary. So what is ß in German, and when should you use it instead of “ss”?

The short answer: ß and ss represent the same sound, but they follow different spelling rules. In general, you use ß after long vowels and diphthongs, and ss after short vowels.

In this guide, we’ll break down exactly how it works, with clear examples so you can use ß correctly every time.

• What is the German ß and what’s the difference from the double s?
• Where does ß come from?
• When to use ß vs ss (simple rules)
• How to type eszett on a keyboard

What is the German ß and what does it sound like?

The meaning of ß in English is eszett. This indicates we have to deal with a special s sound here. There are four ways to make two different s sounds in German:

• s at the beginning or in the middle of a word makes a soft s sound as z in English; example: sehen (to see), reisen (to travel) 
• s at the end of a word makes a sharp sound like the unvoiced English s; 

Example: Haus, Eis

• ß and ss both make a sharp sound like the unvoiced English s no matter where in the word they occur; 

Example: nasse Straße, Fuß, Fluss

If the German eszett and ss make the same sound, why do we have a ß in the German alphabet? The reason for this dates back to the 7th and 8th centuries and has to do with how we use ß and ss.

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How it works

Where does ß come from?

The letter ß has its roots in older forms of written German.

In early German, different “s” sounds were written using combinations like sz and ss. Over time, these sounds gradually became the same in pronunciation, but the different spellings remained.

In medieval writing, sz was often written as a combination of two letters: a long “s” (ſ) and a “z”. With the invention of the printing press, this combination was turned into a single character — what we now know as ß.

So while ß and ss sound the same today, they come from different historical spellings. That’s why both forms still exist in modern German.

When to use ß vs ss (simple rules)

To no one’s surprise, confusion around eszett is widespread – and not only among German learners. This could explain why the Swiss opted out of the eszett circus in 1974 and finalized the decision in 2006 with the ban of the ß from official documents. 

There were attempts to give some guidance for the usage of ß as opposed to ss throughout linguistic history. There were even times of hope to get rid of the eszett once and for all, but there was considerable resistance throughout the population (probably not from school children and German learners, though), so we are still stuck with the problem of when to use ß and ss. The spelling reform of 1996 set the latest rules:

• Use ß after a long vowel or a diphthong (as long as no other consonant follows in the word stem): Straße (street), beißen (to bite).
• Use ss after a short vowel: Pass (passport), hassen (to hate)

Hear the difference between Fuß (foot) and Fluss (river)?

The rule is pretty simple, but if you feel insecure, use a dictionary or a grammar checker to see if you got it right. You could also just memorize the right spelling when learning vocabulary.

There are exceptions to the rule, though. Aus (Out) still has no ß, despite the diphthong preceding the s sound.

Note: There is never ß at the beginning of a word. This probably explains why we didn’t have an uppercase eszett for the longest time. As this caused problems in the German passport, where names are written in capitals, an uppercase ß was introduced in 2017 to differentiate between Herr Strauss and Frau Strauß who would probably have been mistaken for a married couple STRAUSS at the airport before 2017.

How to type eszett on a keyboard

If you have to use eszett in an email for example, search the “Insert symbol” function for ß. Alternatively, press ALT and type 0223 on your PC or hold down Option-S on your Mac. If you have a German keyboard, you will find the key for ß to the right of 0 (zero). 

So, what is the letter ß?

The German ß (Eszett) represents the same “s” sound as “ss”, but it follows different spelling rules. While it developed from older letter combinations like sz, today it’s mainly used to distinguish vowel length in writing.

The key rule is simple:

• Use ß after a long vowel or diphthong
  → Straße, beißen
• Use ss after a short vowel
  → Fluss, hassen

This is the main difference between ß and ss in German, and once you know it, the choice becomes much easier. And if you’re ever unsure, you can always do what the Swiss do and just use ss.