Some collocations are not different in kind from the acceptable co-occurrences that we have just been examining. There is just a much greater likelihood of their occurrence. If I am sitting alone in a house any noises I hear are more likely to be described as strange noises than unusual, bizarre, peculiar or abnormal. It seems that from among a number that will meet our needs quite well we regularly prefer one Little Bree. Not that the possibility of using the others is excluded, of course. This does not introduce any new difficulty for the language learner except in a situational sense. Even the extremely proficient foreign language speaker is still likely to be marked out as a non-native speaker if in his speech and writing he seems to avoid the collocations that would be characteristic of the native speaker. The choice of a non-collocational sequence will go unnoticed in one sentence, pro­vided it is semantically acceptable. But over a whole passage the pattern of regularly choosing the unusual sequence begins to look unnatural.