Portugés- wrong way

Português -rigth way

Algumas dicas para te ajudar:

1)"Eu queria CONTAR-LHES"...  reealy formal (looks like my portuguese teacher talking in the class) . You could say : contar pra vocês. Sounds better

2) "Eu acho que é muito dificil do que eu achava ": Here you are comparing two things, on this case, 'what i think' whith 'what you thought'. And to do any comparison you need to use the  COMPARATIVO (comparative term) -mais, or maior ("maior" is exclusive to compare size) :

Ex: This is harder than that: isto é MAIS difícil do que aquilo

hard-difícil

harder than- MAIS difícil do que ( no problem to say: MAIS difícil que)

big-grande

bigger than- (as it is a size compare you just use MAIOR)- MAIOR do que

**observation: doesn't exist "mais grande do que". as I said it is a size comparing, so you will use MAIOR instead MAIS GRANDE

3)last thing: There is an better expression to the phrase that I comented on the the topic 2 .The phrase you wrote isn't wrong, but we normaly don't use it. The expression is:

(Isso) é muito  mais difícil do que eu PENSAVA ( or IMAGINAVA). U can use always when there is something harder, that broken your expectation

ex: Viver no Japão é mais difícil que eu pensava (live in Japan is harder than I thought)

Sorry by my english..  hope helped u!