be

extremely, fairly, very, etc.
His attitudes are fairly liberal.

remarkably
relatively
socially

be

comparatively, relatively
comparatively liberal in trade matters

broadly, essentially
a broadly liberal set of policies

politically

on
He is relatively liberal on social issues.

be
become

fairly, very
Add a fairly liberal amount of olive oil to the pasta.

with
She's very liberal with her advice!

Liberal is used with these nouns:
agenda, art, attitude, bias, capitalism, Catholicism, cause, Christian, coalition, commentator, conception, Congressman, Congresswoman, consensus, democracy, economics, economist, economy, education, elite, establishment, faction, feminism, feminist, guilt, hand, ideal, ideology, interpretation, judge, law, media, nationalist, newspaper, orthodoxy, party, philosophy, point of view, politician, politics, press, reform, regime, scholar, senator, slant, socialist, society, support, theology, thinker, thought, tradition, use, value, view, viewpoint, wing