However, whereas, therefore

However: a new sentence

But, although and however all say "and this is a surprise". Their grammar is different:

However usually starts the new sentence, with a comma after it. It can also sit inside it, between commas:

In careful writing, It was late, however we kept going is a mistake: a comma cannot join two full sentences. Use a full stop, a semicolon, or but.

Though has one more job. In speech it can end a sentence, and then it means however: It was late. We kept going, though.

Whereas and while: two different facts

Although says the second fact is a surprise. Whereas just puts two different facts side by side:

12

1. 1The girl is reading,
2. 2whereas the boy is playing football.

Two children: the girl is reading, whereas the boy is playing football. Nothing is a surprise. They are just different.

• My sister likes the sea, whereas I prefer the hills.
• The first film was long, whereas the second was short.

Whereas is common in writing and less common in speech. While can do the same job: While my sister likes the sea, I prefer the hills. But while also means "at the same time as": While I was cooking, the phone rang. When a sentence could mean either, use whereas for the difference.

So, therefore, as a result

These give a result. The grammar splits in the same way as but and however:

Therefore also sits inside a sentence, before the main verb: The shop was closed. We therefore went home. It is formal. In everyday English, so is nearly always the better word.

It was closed, therefore we went home has the same comma problem as however. Use so, or a full stop.

This so is not the so before an adjective (so cold that...): see so, such, too and enough.

Common mistakes