Formal vs Informal Connectors — Register Awareness

English has pairs of connectors that express the same meaning at different levels of formality. But and however both show contrast, but "but" is informal while "however" is formal. So and therefore both give results, but "so" is everyday language while "therefore" belongs in essays. Also and furthermore both add information, but "furthermore" is much more formal. Knowing these pairs and choosing the right register for each situation is called register awareness.

The most important pairs to learn are: but → however / nevertheless, so → therefore / consequently, also → moreover / furthermore / in addition, and because → since / as / owing to the fact that. In everyday speech and informal emails, the simple connectors (but, so, also, because) are natural and correct. In academic essays, reports, formal emails, and exam writing, switching to the formal versions shows a higher level of English. Cambridge B2 First and C1 Advanced writing tasks specifically reward candidates who demonstrate range by using a variety of connectors at the appropriate level of formality.