title_body: Is there any importance of "dots" while constructing alphabets for a language? In English, there is a little dot over small letters of i and j. I am not sure what that dot signifies to - pronunciation or sound.
  
  In Gujarati, Hindi and Sanskrit languages, there happens to be dot over letters which signifies to sound "-n" for example Ganga written in either of three with dot over "Ga" alphabet sounds "Gan".
  
  Is there any importance altogether to have such notations? Why? How do you add the same while devising grammar rules for a constructed language?
upvoted_answer: In English, the dot does not carry meaning. It's just part of the lower case letters i and j. There is no dotless base form. Note that the letters i and j aren't dotted in every font or variant of the Latin alphabet. Notably, there is no dot in Gaelic type.
  
  Turkish, on the other hand, does distinguish between dotless I/ı (representing the phoneme /ɯ/) and dotted İ/i (/i/).
  
  Historically, the tittle was added to improve legibility. In late medieval blackletter, the letters i, m, n, and u were basically all made up of vertical strokes, minimum basically was ııııııııııııııı. So a dot was added to i: ıııiııiıııııııı.
  
  Dots can be used for a variety of purposes: Inuktitut syllabics (a constructed script for a natural language) use dots to indicate vowel length, while the Hebrew abjad uses them as vowel marks (niqqud), so does Tengwar. In Arabic, they are used to distinguish letters that have come to otherwise look identical (i‘jām).
  
  Dots are an easy way to derive one symbol from another.
  
  As jknappen has already said: it's up to you what you want to use dots for in your script or if you want to use them at all.
  
  A thing you might want to consider is the medium your script is supposed to be written on. Dots can be easily produced with ink on paper but they are harder to carve in wood where you might want to use a short line instead. Of course, if it is meant to be mainly printed or displayed by screens, reproducibility is much less of a concern.