"Chan eil dà chù agam."
Translation:I do not have two dogs.
In the Tips section https://www.duome.eu/tips/en/gd, it is explained that both aon and dà are singular and cause lenition. It says " Dà (two) causes lenition and is singular Gaelic used to maintain quite a distinct 'dual' form when referring to two things only. This has broken down in many ways, but it is still important to know that two things in Gaelic are not regarded as plural."