The fact that Arabic letters work at all on modern computers is pretty amazing. In addition to the fact that Arabic letters connect to each other (and so they l

The fact that Arabic letters work at all on modern computers is pretty amazing. In addition to the fact that Arabic letters connect to each other (and so they look different in isolation versus connected), Arabic letters change slightly in look depending on what is next to them: they have similar but distinct forms depending on whether the letter is in the initial, medial, or final position of the word chunk (I say "chunk" because most letters connect to the next letter, but some do not). When writing, you usually know what word you're trying to write, so you mentally "compose" the positions of each letter before writing. But when typing, the computer cannot know that, so the letter forms are constantly changing on-the-fly as you type. The program is constantly looking at what was just typed, and whether it then needs to go back and modify the previous letter to link properly.