The aerorator could be clogged with trash calcium etc.  Another trick would be to locate the valves underneath the sink cut them completely off.   Remove the aeroator turn both Hot and Cold on fully at the faucet then reopen the valves one at a time.  Removing the aeroator and opening the faucet allows any of the calcium that has built up over the years to flow through the faucet once the water is  flowing good say in a minute or so turn the water off blow backwards through the aeroator removing the trash then reattach the aeroator.