Here are some common phrases that you might need, in latin alphabet.

Basic Greek

kalimera: good morning (καλημέρα)

kalispera: good evening

kalinihta: goodnight

yia: hi

yia sas: hi (formal)

den milao elinika: i dont speak Greek

pos ise: how are you

pos iste: how are you (Formal)

ne: yes

ohi: no

poso kani: how much it costs

yiatros: doctor

leoforio: bus

taxi: taxi (same both in english and greek)

efharisto: thank you

parakalo: you are welcome (in response to thank you)

signomi: sorry/ i do apologize

epigon: emergency

prepi: must

den katalaveno: i dont understand

po ine : where is

simera: today

avrio: tomorrow

harti ke stilo: pen and paper

tilefono: telephone

numbers

1 ena

2 dio

3 tria

4 tessera

5 pente

6 eksi

7 efta

8 ohto

9 enea

10 deka

11 endeka

12 dodeka

13 dekatria

14dekatessera

15 dekapente

16 dekaeksi

17 dekaefta

18 dekaohto

19 dekaenea

20 ikosi

21 ikosiena

22 ikosidio

30 trianta

40 saranta

100 ekato

110 ekatondeka

125 ekatonikosipente

190 ekatoneneninta

200 diakosia

300 triakosia

1000 hilia

2000 dio hiliades

5000 pente hiliades

days

Monday: deftera

Tuesday: triti

Wednesday: tetarti

Thursday: pemti

Friday: paraskevi

Saturday: savato

Sunday: kiriaki