Statements start with 'Mae'
Questions start with 'Ydy'
eg. Morgan wants an orange = 'Mae Morgan eisiau oren' (lit:- Morgan is wanting an orange)
Does Morgan want an orange? = 'Ydy Morgan eisiau oren?' (lit:- Is Morgan wanting an orange?)
It may seem odd having two forms of 'is', but it's because the Welsh word order is 'Verb-Subject-Object.
It's easy for English which is Subject-Verb-Object to indicate a question by changing the word order, Welsh needs to indicate a question by having different forms of a verb.