Sal, honestly, R sounds like every toddler to me! I don't know of a toddler his age that isn't tantrumming, and it's def frustration that he can't make himself understood. G isn't saying any phrases either, his words are coming on in that a few weeks ago he was only saying mummy and daddy off his own back, but was saying quite a few others when we said 'can you say' before the word. Now he says bus, car, mini, and a few others when he spots them. He really enjoys trying to repeat a sentence, with varying degrees of success. After each meal I say one word at a time 'thankyou for my breakfast/lunch/tea, can I get down please' and he repeats the ones he can and just random grunts and things for the ones he can't. He gets a 'clever boy, really good talking' after every time even if he's being cheeky and just says 'bus bus bus bus bus' after every word with a big grin! Just before he goes to bed we say 'night night, love you, sleep tight and sweet dreams, and see you in the morning' and he knows where 'you' and 'morning' comes and says them (although morning is more like mow-mee!)
He loves books too, and we just go through them and he points at everything and I have to name it. Sometimes I ask if he can say it too, and sometimes he has a really good go and sometimes he doesn't.
I also find a big help when he's getting cross that I don't understand his, is I say 'show mummy' and offer him my hand, and he'll often lead me to what he wants and point to it.