Researchers from the Eötvös Loránd University in Hungary have found that dogs can recognise certain words and even tell the difference between how the words are being said.
They found that the animals can tell if the words are positive like or negative and can understand the tone of voice used to say them.
They trained a group of dogs to lie really still in an MRI scanner, which is a bit like an x-ray for your brain.
It told scientists how the dog reacted to different things by measuring which part of their brain was used in response the test.
The scientists played the dogs recordings of words said in a happy or a normal tone of voice to see how they would react.
By looking at the MRI scans the scientists found that the dogs recognised certain words, and could tell the difference between how the words were being said, in the same way that humans do.
When the dog was played a recording of a positive message said in a happy voice the scans showed the dogs processed that information in the part of the brain that deals with rewards and happy feelings.
One of the researchers Attila Andics explained that: "This shows… that dogs not only separate what we say from how we say it, but also that they can combine the two for a correct interpretation of what those words really meant."

The official report warned that police behaviour, particularly with stop and search had had a corrosive effect on community relations. A subsequent inquiry by Her Majesty's Inspector of Constabulary identified  an "alarming" 27% of stop and searches in which there were no reasonable grounds to conduct the search.  The Home Office has since announced a consultation on reform.
There is a sense of deja vu with all this. An inquiry into the the 1981 Brixton riots blamed disproportionate use of stop and search. An independent report on Tottenham's Broadwater Farm riots in 1985 blamed racist policing. Senior officers promised improvements then... as now.
The Scotland Yard Commissioner Bernard Hogan Howe has set a target to increase public confidence in the Met by 20% by 2016 and has introduced stricter criteria on the use of stop and search. However, the latest monthly figure for Tottenham and the surrounding borough finds 666 people were stopped and searched - almost double the figure two months before. It is work in progress.
That said, the buzzword in the police at the moment is "legitimacy" - an oft-stated determination that officers return to the values of Robert Peel and the principle of policing by consent.

Cardiff council will discuss the plan for Waungron Road, Fairwater, which it said would cut bus travel times.
However, councillor Neil McEvoy said the plan was just about getting the Local Development Plan (LDP) approved.
Cabinet member Ramesh Patel said the council wanted an attractive viable public transport alternative.
A Liberal Deomcrat-led coalition spent £1m upgrading the site in 2008/09 but it was shut in 2014 by the current Labour council, which said it was not financially viable.
It said the interchange would be "vitally important" for a new public transport route across the city.
But Mr McEvoy claimed the council had kept its plans quiet.
"In politics whenever you don't want to do something you just say we can't afford it," said Mr McEvoy.
"But this is not a question of finance. This is just about getting the LDP approved."
In a statement, Mr Patel said the interchange would cut journey times by allowing people to travel between east and west Cardiff by bus without driving into the city centre.
The site is also next to Waungron Road railway station, which he said would allow more commuters to use both buses and trains.
The LDP is being examined by the Welsh government's planning inspector.
The council said any proposals for strategic transport sites across the city would go through the full planning process, with consultation.
Ever wondered if your dog can REALLY understand what you are saying?
[NEXT_CONCEPT]
When the smoke cleared from the riots triggered by Mark Duggan's shooting, uncomfortable questions for the police emerged.
[NEXT_CONCEPT]
A row has broken out over a bid to create a bus interchange on a closed recycling site, seven years after it had a £1m revamp.