Apertium-recursive/Cookbook

This page is intended to be a collection of solutions to common transfer problems. It is sorted vaguely be complexity, so it could potentially also serve as a tutorial. Functioning rulesets for each of these examples can be found at https://github.com/apertium/apertium-recursive/tree/master/tests/cookbook.

Noun-Adjective Gender Agreement

NP -> adj n { 1(gender=2.gender) _1 2 } ;

This will copy the gender tag of the noun to the adjective.

Reordering

NP -> adj n { 2 _1 1 } ;

This will reverse the order of the noun and adjective.

Agreement across Multiple Levels

NP -> n.$gender.$number { 1 } |
      adj NP.$gender.$number { 2 _1 1(gender=2.gender) } ;
DP -> det NP { 1(number=2.number) _1 2 } ;

These rules will match a determiner, 0 or more adjectives, and a noun and make all the adjectives agree with the noun in gender and the determiner agree with the noun in number. The adjectives will also be output after the noun in the reverse of their input order.

Selecting Output Patterns

v_inf: _.<inf>;
v_fin: _.tense.person.number;
v: (if (1.tense = inf) 1[v_inf]
    else 1[v_fin]);

When outputting a verb, this will not try to add person and number tags if the tense is <inf>.