As an actual native English speaker on this thread, I would use 'cannot' for 'cannot obtain', as it indicates an impossibility, never a choice, but stay with 'can not' in the other cases. I cannot live forever; I don't get the choice. I can not care about this silly thread, but I choose to post regardless. (yes, there are multiple meanings in that one...) While running words together is very German, here that is not always appropriate. When these are choices that could somehow be done, rather than impossibilities, 'can not' is better - but as imo 'can not' can also covers the other case of impossibility where 'cannot' fits best, and the reverse is not true, 'can not' can be the safer choice - particularly for non-native speakers and technical documentation. (The can't contraction covers both.) So Gerrit's choice is best, though in those cases I'd reword the technical documenation and say something like 'is unable to' to be perfectly clear that there is no choice in the matter. That avoids can/may permission ambiguity and confusion as well. Some post-hoc rationale is at http://alexfiles.com/cannot.shtml http://www.wisegeek.com/what-is-the-difference-between-cannot-and-can-not.htm (Meta: we're discussing grammar nitpicks to a standards-track update to an aspect of a protocol that's currently on life support with a hack to get through NAT via UDP tunnelling to try and get some installed base? When did the IETF jump the shark?) > -----Original Message----- > From: dccp-bounces@xxxxxxxx [mailto:dccp-bounces@xxxxxxxx] On > Behalf Of Gerrit Renker > Sent: 04 March 2011 11:55 > To: Lars Eggert > Cc: dccp@xxxxxxxx group > Subject: Re: AD review: draft-ietf-dccp-tfrc-rtt-option-03 > > Lars, - > | > than 4 can not be determined: such samples have to be > discarded. > | > | Nit: s/can not/cannot/ > | > I would like to ask if we could keep it as it is, the > suggestion confuses me: > can is a verb, not the negation, cannot is spoken language, > the document is written text. I actually replace everywhere I > see this the other way around, since I read somewhere that > cannot in written text is not considered good style. If you > can give a rule for the above, I am willing to be educated on > the matter. >