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how to say" HELLO"."THANK YOU".in dutch?

Hello = Hallo
Thank you = Dankje wel

Hy
In the morning you say goedemorgen
at the afternoon you say goedemiddag
and in the evening you can say goedenavond

just additional:

1) The 'a' in hallo is pronounced as the 'a' in afternoon. As for the rest, it's pronounced the same as hello

2) You is both formal and informal. A formal thank you is 'dank u'/'dankuwel'. Informally, it's 'dank je'/'dankjewel'. Again the 'a' is pronounced the same as above. The 'u' is pronounced as a German 'ü' (I don't know if you're familiar with it?), 'je' is prounced as y in you and the a from as in a (cat/dog/whatever). 'wel': w holds the middle between an english v and w. the e-sound is like in best.

Of course you have different sayings for hello (see WDF81) and thank you...

hello = hallo, goedemorgen (good morning), goedemiddag (good afternoon), goedeavond (good evening)
thank you = dank u