1. Wendy claims that Frank's birthday is the seventeenth of August - yr ail ar bymtheg o Awst.

Seventeenth is an ordinal number - and we looked at some of these recently.

Let's remind ourselves of them again. The first four are irregular.

cyntaf first; ail second; trydydd third; pedwerydd fourth.

They then follow a more regular pattern from the fifth to the tenth:pumed; chweched, seithfed, wythfed, nawfed, degfed

But when we reach the eleventh of the month we say yr unfed ar ddeg or literally 'the first on ten'. As we've just heard, cyntaf is the word for first, so you'd expect eleventh to be y cyntaf ar ddeg, but guess what - it's irregular! So it becomes yr unfed ar ddeg.

Likewise sixteenth is yr unfed ar bymtheg (literally the first on fifteen) and the seventeenth is yr ail ar bymtheg (literally the second on fifteen). But don't worry if you find the ordinal numbers daunting. If you want to say when your birthday is, it is perfectly acceptable to say Awst un deg saith. - literally August seventeen.

2. Conversations in Welsh seem to be peppered with the little word 'na', which doesn't seem to make any sense as a negative in certain instances. Well, that's because it isn't.

In discussing the uncertainty of little Frank's date of birth Wendy says:

'Na pryd gafodd Frank 'i eni - That's when Frank was born.

and

'Na'r gwir - That's the truth'.

'Na' here, is in fact an abbreviated form of dyna 'that'. 'Dyna' therefore becomes 'Na'.

3. When Brian reproaches Jac for running off with his wife, he says:

Chdi ddygodd fy ngwraig i.

You know that the -odd ending indicates the past tense. For example - edrych which means 'to look' becomes edrychodd in the past tense - 'he looked'. But it's not always as easy as this. Dygodd is the past tense of the verb dwyn which means ' to steal'. It's dygodd not dwynodd, which is what you'd expect.