Combining Ogonek

It changes the letter before it; the writing system decides how.

The hook marks nasal vowels in Polish spelling: vowels spoken with air flowing through the nose. An ancestor appears in Old Polish manuscripts around 1300, but it was a special nasal-vowel letter, not this separate combining mark. During the sixteenth century, print and spelling conventions moved toward hooked letters such as ą and ę.

The Latin alphabet lacked dedicated letters for Polish nasal vowels, so writers used extra letters, letter pairs, and marks. Lithuanian later borrowed ą and ę from Polish, then extended the pattern to į and ų; the hooks stayed after those vowels shifted from nasal to long, oral sounds. Americanist phonetic transcription (a way to write speech sounds) and Navajo spelling also use the ogonek for nasalization.

how do I type the combining ogonek

Put the base letter first, then insert the combining mark.

The mark is stored after its base even though it is drawn underneath. In a Unicode hex-input tool, enter 0328 after the letter; exact keystrokes depend on the tool. An editor may normalize the two-character sequence into one precomposed letter without changing its canonical text. If a font or layout engine lacks support for that letter-and-mark pair, the hook may drift or appear beside a dotted circle while the sequence remains intact.

is this an ogonek or a cedilla

No. The ogonek hooks right; the cedilla hooks left.

They are separate marks, so the spelling convention decides which one belongs in a word. A cedilla is not a typographic substitute for an ogonek.