In the previous section the data-collection methods were kept as equivalent as possible to try to get a reasonable comparison between the three groups. This meant analysing the errors in fairly traditional, letter-based categories. This type of analysis is unrevealing when applied to language systems except at a gross level. This section takes four main categories from the last section as a skeleton, that is to say leaving out grapheme substitution and ‘other’ except incidentally, but deals in more detail with sub-categories of errors, turning to the amplified L1 and L2 corpora and varying the order of types to get a smoother order of presentation. Errors are here mostly taken as representative rather than comparable in figures. The intention is to provide a more detailed description of typical L1 and L2 errors and to lead towards questions concerning the involvement of the two routes and their relationship to the user’s L1.