In addition to these, other types of knowledge should be considered such as knowledge of the spelling of a word and knowledge of its pro- nunciation, including stress. As regards spelling there may be different acceptable written forms for the same word within the same variety of English(e.g. «hello/ha- llo/hullo») or, most commonly, due to the fact that they belong to diferent varieites as happens with many British or American English terms (e.g. (BrE) or American English terms (e.g. (BrE) or (AmE)