One of the great (!) things about Gaelg is that initial letters to words often change.
These are often referred to as mutations. We've already met one:
Thie = house but my hie = my house
Here's another example in which the original word starts with a 't'
Tholtan = ruin but my holtan = my ruin
This change occurs if the word follows 'my' (my) or 'dty' (your)