"I like cycling a lot."
Translation:Is toil leam rothaireachd gu mòr.
I know "I like a lot cycling" is not normal word order in English and that in English the word order has to be "I like cycling a lot", but Gaelic word order is not dependent on English is it? A Google search (in quotes) for either "Is toil leam gu mòr" or "Is toigh leam gu mòr" produces numerous results, most frequently followed by the pronoun e. Are these all incorrect Gaelic, or is there something specific about rothaireachd that makes the word order that I suggested incorrect?
Historically it was toigh leam. Because it sounds like toil leam, which almost makes sense, they just got confused. It is only in the last few years that toil leam became the preferred version.
This is called an eggcorn. I am not aware of any other examples in any language where one has been formally adopted into the spelling system although I am sure there are some. I think there may be some in Middle English that we now just accept. Can anyone think of any in any language? The Wiki article I reference above does not mention any.
Because it isn't in Gaelic or English here. It is a noun, meaning the act of cycling. It is an activity that you enjoy. A' rothaireachd means you are 'at cycling'. The English word cycling is a multipurpose word, which causes lots of confusion for linguists, probably a combination of the Celtic verb noun, the German gerund and the French present participle. But in this particular case it is clearly acting as a noun, with no need for any preposition in front.