Expressions used in Everyday Spoken English in Social and Professional contexts
Get at is a phrasal verb which has a number of meanings that can be used in a professional or social context. To get at something can mean to have access to something for example, 'I can't get at the box because I'm too short'. Informally or colloquially to get at something can mean to imply or suggest something indirectly, so you can say. 'I think I know what you're getting at,' or you can ask someone 'what are you getting at?'
To get at something can mean to access something or to reach for or obtain something especially when it is difficult or challenging. For example, you might open a laptop to get at the hard drive or use a ladder to get at something in the attic.
To 'get at' someone can mean to irritate or annoy somebody. If you 'get at someone' you might critisise them frequently or constantly behave in a cruel way towards them, similar in meaning to 'being on someone's case'.