Previous studies across languages (English, Spanish, French) have argued that perceptual salience and cue reliability can explain cross-linguistic differences in early comprehension of verbal agreement. Here we tested this hypothesis further by investigating early comprehension in Greek, where markers have high salience and reliability (compared to Spanish and English) predicting early comprehension, as in French. We investigated two and three-year-old Greek-speaking children's ability to distinguish third person singular and plural agreement in a picture-selection task. We also examined the frequency of these morphemes in child-directed speech to address input effects. Results showed that three-year-olds are sensitive to both singular and plural agreement, earlier than children acquiring English and Spanish, but later than French, and despite singular agreement being more frequent than plural agreement in the child corpus. These findings provide further support for the role of salience and reliability during early acquisition, while highlighting a potential effect of morpheme position.