Phrases Asking for Clarification

I'm having trouble understanding…

Meaning

I'm experiencing difficulty comprehending…

Translation language

John: 'The system's architecture is modular.'
Alice: '<b>I'm having trouble understanding</b> what 'modular' means in this context.'
John: '<b>I'm having trouble understanding</b> the specific steps in the strategy.'
Alice: 'The implementation strategy requires careful planning.'