Final answer:
In the first stage of late adulthood, enhancing vocabulary is a common developmental task for language and communication skills, as it builds upon existing knowledge to improve articulation and understanding.
Step-by-step explanation:
A common developmental task in the first stage of late adulthood in terms of language and communication skills is Enhancing vocabulary. During this late stage of life, adults may build upon their existing knowledge of words and phrases to better articulate themselves and understand others. This ability to enhance vocabulary contrasts with mastering phonetics or learning a new alphabet, which are tasks more typical in early language development, or developing writing skills, which is a skill often focused on during school years.