As a Spanish language teacher I have learnt to value the ever-valiant attempts made by students in their effort to speak their new language. It is clear that, when using a foreign language, the sound of their speech will be slightly, if not totally different from the one of the natives. This means they are never free from making “mistakes”; though this is far from being an obstacle, instead being is a great way to improve.
Nonetheless, one of the most frequent kinds of mistakes heard in the classroom represents a good clue in appreciating the gradual learning process of new grammar: the error of ‘regularization’.
In a way, second language students take the role of young children acquiring their mother tongue. There are wide differences from a psycholinguistics point of view, as children do not have a previous grammar to hinder the internalization of a new one (that is why we ‘acquire’ our first language when we are young, but ‘learn’ a second one when adults).
Once we have made a distinction between adult students and children, I would like to mention one of the coincidences I found: there is a clear tendency make words regular. For instance, it is not unusual that a student says “no sabo” in order to say “I don’t know”, which does not exist in Spanish, and is a mistake for sure (“no sé” is the correct form). However, more important than the specific inaccuracy, is the fact they have shown that they are not just learning a list of words by heart, but learning a new grammar. They have learnt the rule that says ‘take the ending off the infinitive and add ‘o’ to get the form for the present indicative first person singular’. In this case, it didn’t work because for irregular verbs there are no general rules. However, this student has shown themselves to be capable of conjugating most Spanish verbs correctly, even if it is the first time they’ve come across them – but now it’s time for them to memorise the exceptions!