The distinction between lexical and grammatical aspect is not particularly relevant when it comes to cross-linguistic comparisons. Each language has a number of ways of describing events with respect to their duration, completeness, repetition, etc. which is broadly labelled as aspect. Sometimes aspectual meanings are separated from other types of meanings (like mode, manner, time, sequentiality, evidentiality, etc.), more often they are blended together.
Each language has a unique blend of these expressions that determine what gets routinely said by its speakers. Each language forces speakers to make different commitments as to what is specified and what is not. This could be at the level of grammar or lexicon or somewhere in between. (One of the reasons 'construction' is a better model for this than grammar or lexicon.)
For instance, most Czech deverbatives contain information about progress or completeness. So for instance, there are two different ways to say 'Shopping is tiring.' that clearly indicate whether it's the process or the complete event. In English, there are ways to express that distinction but they would require a discursive solution. What happens, however, is that most of the time English speakers just don't bother. It's not information that is all that relevant most of the time to Czech speakers, either. But the language forces that commitment. When you're translating, you may discover that this commitment makes things difficult. This is something translators deal with every day.
So, in this sense, languages are broadly commensurate when it comes to the communicative needs of their respective speakers. But they are not commensurate when it comes to replicating each other's grammatical commitments.
