My SSiW (Southern Welsh) challenges have now introduced another way of saying "FOR’
In previous challenges I have become used to using AM for “for”. Now a different way of saying “for” has been introduced as “AR GYFER”. Are these two ways of saying ‘for’ interchangeable or are there grammatical rules for which to use??
No, although both can mean ‘for’ in various senses, they’re not quite interchangeable. Ar gyfer can mean ‘for’ in the sense of “for the benefit of” or “on behalf of” (‘am’ can’t) but cannot be used when the ‘for’ implies “in exchange for” or when the ‘for’ involves a period of time (‘am’ can).
Have you got Gareth’s “Working Welsh” book? He explains them both more fully on pages 9 (am) and 14 (ar gyfer)
Diolch Siaron. I understand it now. I’ll just have to get used to hearing it in different contexts. I don’t have Gareth’s book “Working Welsh”. At my current level of learning - I’m on Challenge 5 of Level 3 in SSiW - I am reluctant to get too involved in the grammar. At this stage I am just learning to speak in the same way that I’m hearing on SSiW. However, there are times when I get confused about the use of different words for what appear to be the same thing. Hence this post. Would you advise me to have a copy of “Working Welsh” at my stage of learning??
Siaron - I have had a look around and there are quite a few books for Welsh learners. If I had to choose one, which would you recommend?
Yes, I would definitely recommend it - level 3 is not too soon at all! It’s not a full grammar book in the way his others are, it’s more of a really handy guide to 200 tricky bits that often trip learners up, and good to dip into for things just like am/ar gyfer. He also explains North, South and spoken variations. 
David, I’d second that recommendation. I love working Welsh. It’s super practical and useful for ordinary speech. It’s also so well written and really quite entertaining - I never thought a book about the mechanics of a language could be such a page turner 
Diolch Siaron. I’ll get a copy
Diolch Emma - I’ll take your recommendation and get a copy
Nurse! Case in urgent need of assistance over here! 
Cool your jets Gareth. I have ordered your book 
Oh thank goodness - another soul saved just in time!!
Where can you buy Working Welsh? The places I’ve looked it’s about £35.
Yes, the RRP is £34.99, but it’s well worth it.
I purchased my paperback copy from Amazon at £28.99