Wine turned out like syrup

[jmini]

Me and my wife just made some wine but it turned out more like syrup rather than wine. Could we add more yeast and start it over?

 

[KevinM]

What were your ingredients and steps? What is the alcohol reading? These are the things that would prevent fermentation.
When you say like syrup, do you mean body or sweetness?

 

[jmini]

Grapes,blackberries and.mulberries. Added half the sugar and all the yeast. Fermented for about 3 weeks then added the other half of the sugar. Put it on airlock. It's tasted just like syrup, thick and sugary.

 

[Raenon]

Grapes,blackberries and.mulberries. Added half the sugar and all the yeast. Fermented for about 3 weeks then added the other half of the sugar. Put it on airlock. It's tasted just like syrup, thick and sugary.

Without knowing how much "half" is, and the batch size, no one can do much to offer advice.
How much fruit, of what kinds, how long has it fermented in total and did you get any hydrometer or refractometer readings?
Where did you get the recipe?