So
welcome- dobro pozhalovat( t on the end you should say gently)
(no,)thank you - (net,)spasibo
Yes - da
No- net
Give me a book, please - Dai mne knigu, pozhaluista; Dai mne ,pozhaluista, knigu; Pozhaluista, dai mne knigu. (give - dai; me - mne;book - kniga)