Slips of the tongue can be useful for understanding the psycholinguistic processing of speech output. Here is an interesting slip that occurred with a news reader on the BBC.
01: amazingly (.) the mum of four from West Sussex 02: says she wouldn't turn the back the clock
The error occurs in line 02. The intended output was ‘turn the clock back’. Interestingly, this news reader did not correct the mistake which is what normally happens when we make speech errors. This could have been due to he colleague who came in with the next item.
This error would be classed as ‘word exchange’ although it is unusual in that exchanges usually occur between words of the same grammatical category, such as noun and noun. In this case, the exchange is between noun and adverb. The insertion of a second article (‘the’) is also unusual.