How do I activate ligatures?
Ligatures were popularised during the era of movable type, when single block ligatures would replace unsightly glyph combinations. Opentype allows a high degree of flexibility when working with ligatures by offering two options: standard and discretionary. Standard ligatures tend to include the common combinations of fl, ff, ffi, and ffl. Discretionary ligatures include more unusual combinations such as ct, fb, fj, st, ty and many more.
In Adobe Illustrator, ligatures are accessed via the OpenType panel by selecting Standard Ligatures and Discretionary Ligatures:
In Adobe InDesign, ligatures are accessed via the character panel by selecting OpenType > Standard Ligatures and OpenType > Discretionary Ligatures: