I can't recommend a book or anything, but a lot of languages incorporate pronouns and the verb in one word. This is that scenario. Spanish does this as well. The Spanish word for eat is comer. When saying "I eat" its como(the er to the o denotes it is I), you eat is comes, we eat is comemos, etc.
No, they're different.
Ithim / itheann mé = I eat
Tá mé ag ithe = I am eating.
Native English speakers will appreciate the difference between these two.
For nonnative English speakers, they might seem the same - but have a think about it. The first implies regularity (that one generally eats), but does not mean that any eating is being done right now. The second implies that eating is ongoing (though the eater might not be eating at this precise moment: the crucial thing is that he or she has started eating and not yet finished!).
Definitely. The distinction between these two forms seems to be a common feature of all the languages native to Ireland and Britain, though it's uncommon elsewhere in Europe.
'Itheann sé' = he eats (regularly)
'Tá sé ag ithe' = he is eating (now). Literally: 'He is at eating', which might remind English speakers of the archaic/dialectical forms like "he's a-eatin'" or "he's a comin'"
I am learning Irish taking into account two things: Spanish is my mother tongue, so in that respect I compare Irish to Spanish in terms of inflections, conjugations rules and the like. Then. .. and the most IMPORTANT. .. it is a MUST you forget you have an given level of English. Otherwise, you will feel everything is upside down. So... if you're really willing to learn Irish, total amnesia! Act as if you didn't know a single word in English. It's hard, though it's the only way to avoid letting yourself down. Good luck! ☺