what is the difference between ar and ar with dots on top of the letters

The "ar" and "ar" with dots on top of the letters, also called "är," are two different alphabets or writing systems.

1. "Ar": This refers to the Latin alphabet, also known as the Roman alphabet, which is the most widely used alphabet system in the world. It consists of 26 letters, ranging from A to Z, which are used to write many languages, including English, Spanish, French, and many others.

2. "är": This refers to the alphabet used in the Swedish language, specifically for writing the vowel sound /ɛː/. In Swedish, certain vowels can be modified by adding diacritical marks, such as dots or other symbols, to change their pronunciation. The dots on top of the letter "a" in "är" indicate that it is pronounced differently from the standard "a" sound.

To differentiate between the two, you can observe the context in which the letters are used. If you see the letters "ar" in a text, it's likely to represent the Latin alphabet. On the other hand, "är" with the dots on top is specific to Swedish and denotes the pronunciation of a specific vowel sound.