I'd need help buttoning it up.
'Abbottonare' — 'ab-bot-to-NA-re'. Six syllables. Double 'b' and double 't'. Stress on fifth syllable.
For complicated garments with back zips, small buttons or complex closures. Italian boutique staff are happy to help — this is part of the service.
'Avrei bisogno di' = I would need (conditional, polite). 'Aiuto' = help. 'Ad abbottonare' = to button up ('a' + infinitive). 'Avrei bisogno' is more polite than 'ho bisogno'.
Può aiutarmi con la cerniera?
Can you help me with the zip?
'Cerniera' = zip — asking for help with a specific closure
Ho difficoltà con i bottoni sul retro.
I'm having difficulty with the buttons at the back.
Explaining the specific problem — back buttons
Come si indossa questo?
How do you put this on?
When a garment's opening system isn't obvious
Italian boutique assistants are trained to assist with dressing in a professional and respectful manner. Asking for help with complex closures is completely normal and part of the personalised service Italian retail is known for.