Final answer:
Typical of informal correspondence is the use of abbreviations and colloquial language, which reflects a conversational and relaxed tone, distinguishing it from the formal requirements of academic or professional writing.
Step-by-step explanation:
The practice that is typical of informal correspondence is c) Using abbreviations and colloquial language. Informal correspondence, such as emails to friends or casual messages, often features a relaxed tone and style, evidenced by the use of slang, contractions, and colloquial expressions. This contrasts with formal correspondence, which would follow a structured and formal tone, avoid colloquialisms, and might include detailed references and citations common in academic or professional writing.
Informal writing typically adopts a conversational tone, reflecting the way people speak in day-to-day life. It is common to see informal diction, such as using 'kids' instead of 'children', or phrasal verbs that might not be used in more formal contexts. Such language choices help to create a friendly and relaxed atmosphere, making the communication feel more personal and accessible.