formal writing

[Unregistered]

Hello,
my name is jan jonk, and I teach English at a comprehensive school in Holland. The level is intermediate to advanced. I have two questions to put to you concerning formal writing.

1. Is it permitted to write CAN + NOT as two separate words? I know it was not possible some years ago, but I have the feeling that the English language has moved on since then.

2. We are also having a dispute about the division of paragraphs in formal letters. Skipping a line has always been permitted, but what about indentation; is that on the way out?

Yours,
Jan Jonk

[colloquium]

1) Yes, absolutely. Cannot is more common but depending on context and/or just personal preference both are acceptable.

[Anglika]

2. We are also having a dispute about the division of paragraphs in formal letters. Skipping a line has always been permitted, but what about indentation; is that on the way out?

You can choose which to follow: one line space between paragraphs and no indent, or indent and no space between paras. There is no absolute rule.