Every form but the headword, the genitive and the plural is worked out by the spelling rules in the grammar guide, so what you see here is what the guide teaches. Checked by a fluent speaker.
In a phrase ✓ Verified
- Chan eil mi a' tuigsinnI don't understand
- Tha mi a' tuigsinnI understand
- Tha mi a' tuigsinn barrachd na as urrainn dhomh a ràdhI understand more than I can say