How does Hindi add letters for sounds borrowed from Arabic and English?

To represent sounds borrowed from languages such as Arabic and English that were not originally present in the Devanagari script, modern Hindi utilizes a diacritic mark called a nuqtā (an Arabic term meaning "dot").1

By adding this dot beneath existing Devanagari characters, writers can create new symbols to accurately reflect foreign phonemes. Examples of this adaptation include:1

• क़ (dotted k): Used to represent the sound /q/.1
• ज़ (dotted j): Used to represent the sound /z/.1
• फ़ (dotted ph): Used to represent the sound /f/.1

While these modifications allow for precise phonetic representation, it is worth noting that in some contexts, these borrowed sounds have historically been replaced by native Hindi equivalents (for instance, /f/ might be rendered as /ph/ and /z/ as /j/).2