I play trombone, and can play all the clefs on that. To read tenor clef, you read it as treble clef (in Bb), add 2 sharps to the key, and sharpen the accidentals - piece of cake.
Now I've just worked through grade 6, and managed to scrape through the tenor clef passages by memorising them, but I was shown one of my new grade 7 pieces the other day, and it's all in tenor clef. This means that really I'm gonna have to knuckle down and learn it.

Does anyone have any advice, as not being able to read it really frustrates me and I find it difficult to keep persivering

HELP!

just practice. you can have all the mnemonics and memory stuff you like but the only way is to use it. try sightreading as much as you can even if its slow at first. give it a couple of months and itll be there.

On the cello, I always got taught to play one string up. So if it was an A on the G string in bass clef, then in tenor clef play one string up, so play an E on the D string. I used to do that for ages, until eventually it sunk in. I never really had any problems with treble, as I play piano, but i'd say the best thing is to do loads of sightreading.

I think it's better to learn to read the notes than to use a "trick" to figure it out. Use mnemonics etc. Being able to read it away from your instrument will be a very good start. Try singing with note names.

When reading alto clef, I have the problem that I keep reverting back to tenor clef. Until I get my head around that, I'll be constantly reminding myself as I'm playing of where middle C is. It helps.

Thanks for your help so far guys, but what are nmenomics?

Another exercise is to take a short piece of music in bass clef which isn't too hard, and which perhaps you know superficially but not in detail. Then write it out by hand transposed into tenor clef, and then learn to play it from your tenor clef version.

Don't use a computer for the transposition as you need to learn to mentally associate the notes in both clefs.

P.S. zauberfagott, where do you see alto clefs? Didn't think they appeared in bassoon parts...

I use different clefs to tranpose my music into different keys. And I used to play viola parts in a string ensemble (bassoon works very well with strings, still sounds like a bassoon but they blend very well). And I played viola parts for composition students wanting to try out their works with real instruments. (Right now there's only 2 viola players at uni, 1 is a violinist and gives you evils if you ask him to play and the other is a violist but she's not very confident)

But I was a bored bassoonist and would read clarinet, alto sax, french horn and cor anglais parts. So, I can read any clef fluently away from an instrument, and I can read treble clef, french violin clef, bass clef and tenor clef fluently on any instrument I know how to play (as long as I know enough notes on the instrument, of course). I can read alto and mezzo-soprano clef fairly well, and I can read soprano and baritone clef if I must, but I'm not as practised. Reading a clef and playing from a clef are sompletely different skills! But if you can't read a clef away from your instrument, there's no way you can play from it...