(a-) might weaken its doubling capacity. The presence of this separable prefix also makes the boundaries between the reduced infinitival reduplication form and the prefix hard if not impossible to determine. Thus, in the example above for , an argument could be made that the prefix a- is left off, while the full reduplicated form is used: In this case, the prefix would be omitted, which is normally not permissible for separable prefixes, and in its place, the reduplication form is used. Meanwhile, is not reduplicated when used in a subordinate clause or in the past tense. In such instances, doubling would result in ungrammaticality: Past tense example with : The same is true for subordinate clauses and the verb : Subordinate clause examples with : In order to achieve grammaticality in both instances, the reduced doubling part would have to be taken out. and optionality of reduplication While 'to start, to begin' is quite restricted when it comes to reduplication effects, the phenomenon is more permissive, but not mandatory in the verb 'to let'. While present tense declarative sentences are generally ungrammatical when remains unduplicated, this is not true for past tense and subordinate clauses, where doubling effects are optional at best: Past tense example with : Subordinate clause example with : In the use of this form, there are both geographical and age differences. Reduplication is found more often in the western part of Switzerland than in the eastern part, while younger generations are much more inclined to leave out reduplication, which means that the phenomenon is more widespread in older generations. and : stronger reduplication Ungrammaticality in reduplication of 'to start, to begin' in the past tense and in subordinate clauses as well as the somewhat more lenient use of reduplication with 'to let' stand in contrast to doubling effects of the motion verbs 'to go' and 'to come'. When the latter two verbs are used in other utterances other than a declarative main clause, where the finite verb traditionally is in second position, their use might not be mandatory; however, it is correct and grammatical to double them both in the past tense and in subordinate clauses: Past tense example with and : As outlined in both examples, the reduplicated form of both and can but does not have to be used in order for the past tense sentences to be grammatical.Notably, it is the reduced