Can omitting -ly suffix of an adverb cause ambiguity?

Sometimes, I forget to use the proper form when an adverb is required. Or sometimes it simply doesn't appear to me one is required, unless I actually consider the grammar of my sentence. I suppose that's mostly because in my native language (German), there is no morphological difference between an adverb and an adjective.

This led me to wonder:
Is this distinction in English merely an idiosyncrasy or can I really semantically convey something other than intended, if I omit the suffix by mistake?

Leaving out the '-ly' is more of a marker of non-standard English. That is, in more formal occasions, one usually keeps the '-ly' but informally or in regional dialects it is more common to drop the '-ly'. The prescribed grammar rule is to, except for, well, exceptions, form an adverb from the adjective by the suffix '-ly'. There is almost no ambiguity because of the position of the word.

There may be instances were a semantic ambiguity could arise, but they are rare, so you would be safe -semantically- in dropping '-ly'. However, you probably don't want to make that a habit, because as an ESL speaker, most people will call the '-ly' dropping incorrect, or even uneducated (because of its association with non-standard speech).