How can I make letter combination short-cuts?

Hi, in the font that I’m working on - I want to create letter combination short-cuts.
By this I mean, when I type in “a” followed by an “e”, I want the symbol “æ” to appear automatically taking the place of the individual letters.
Or when I type the letters “t” and “h”, like in the word “the”, I want the symbol “ð” to appear.

I want these symbols to appear without me having to type in an Alt+number type of code on word, etc.

Is there a way to do so? If so, how can I go about doing that?

If you always want ae to become æ even in words like æroplane then adding OpenType glyph substitutions is the way to go. FontCreator doesn’t currently support glyph substitution so will have to use a third-party application like MSVOLT to do that, or see this tutorial thread on Adding OpenType Features.

Remember that most applications do not support OpenType glyph substitutions so these fonts will not work everywhere.

The other approach is to use autocorrect or customised keyboards for this.