19.4 present simple, present perfect, past simple 2 We (1) develop / have developed / developed a didactic method for addressing the high level of irregularity in spelling and pronunciation. In our method, we (2) combine / have combined / combinednew words, or words that nonnative speakers regularly (3) have / have had / had difficult in pronouncing, with words that they are familiar with. Tests (4) are / have been / were conducted on 2041 adults who (5) are / have been / were selected at random from higher education institutes in 22 countries. The results (6) reveal / have revealed / revealed that as many as 85% of subjects (7) manage / have managed / managed to unlearn their erroneous pronunciation, with only 5% making no progress at all. We (8) believe /
