Most studies show that the members of rural communities who are most likely to migrate to urban centers are those who have been to school. The studies seem to show a consistent positive correlation between an individual's level of education his propensity to migrate. REASONS (1) The income gap between what the 'educated' ones can earn in urban areas compared with their rural opportunity cost is larger than it is for the illiterate ones.(2) The educated ones are more likely to obtain a lucrative modern sector job. But because jobs are scarce,a large proportion of those who migrate often remain unemployed.
In my country both the educated and uneducated are leaving the rural area for cities. The main reason, as you said, is the lack of employment opportunities in the rural areas. These illiterates will gradually learn how to speak the official language, and within a few years, they will be used to Urban life. Many uneducated people migrate to big cities in̈ the US and still survive.
But other factors contribute to the high level of rural-urban drift in my country. Poor infrastructure, insecurity, and environmental concerns are forcing them to move where they can get a better life. Some rural areas don't have electricity, good roads, water, or other amenities. Some places are facing a high rate of criminal activity. Flooding is also a major challenge in rural areas in my location.