Exceptions for contextual alternates via keys


i’m a dutch novice with glyphs and have created a font in which i have defined a number of contextual alternates and the features that go with them. but sometimes the alternates must not be used.
f.i.: in the word ‘ring’, the ‘n’ and ‘g’ are connected, because ‘ng’ has a special sound in dutch. therefore i created a feature that replaces those two characters by a contextual alternate for ‘ng’. that works fine.
but in the word ‘aangaande’, the ‘n’ and ‘g’ should not be replaced, because here the ‘n’ and ‘g’ do not belong to eachother.
is it possible to use f.i. a keyboard combination to prevend the feature from kicking in ?
or perhaps there is another way to create exceptions to a feature ?

thanks for any help
rené bosch
studio 103

You can add more complex contactual rules to the font to find those exceptions, but that might be to much and still don’t work in all cases.
If you can control the text, you can add a ZERO WIDTH NON-JOINER (0x200C) to prevent the ligature.