I go to Chinatown often with my big 80-lb dog.
To make kids and adults smile, I zap them with words I’ve been taught:
(absurd transliterations)
Dog=go
Big=dai
(pointing to dog)=(pronounced like) “die go”
Smart dog=(pronounced like) “sigh go”
OK.
What is–
“nice dog”
“calm/gentle dog”
“pretty dog”
?
Finally, if I think I can hack it:
(pointing to head w/ smile):
“I’m smart”
“I know Chinese”
Thanks,
Leo
It’s interesting that “go” is dog in Cantonese. In Vietnamese “gâu gâu” is the sound a dog makes, like arf or bow-wow.
I can’t help with your translations, but at least my tangent gets you a bump, right? 
Oh, and you might run into Vietnamese speakers even in Chinatown. So, just in case:
“nice dog” chó ngoan
“calm/gentle dog” chó bình tĩnh
“pretty dog” chó đẹp
“I’m smart” Tôi thông minh
“I know Chinese” Tôi biết tiếng Trung Quốc (also tiếng Hoa)
I know Vietnamese Tôi biết tiếng Việt
I’m not sure how you are pronouncing it, but just FYI, dog is pronounced, roughly, “Gow”, rhymes with “Cow” (the mooing kind). It also has a rising tone, but you probably don’t want to get into tones right now. Here are some things that may be useful:
Hoe Duck-yee (the “duck” should be a higher tone than the other two syllables): “Very Cute”
Gow Hoe Leng: “Pretty Dog” (literally, “Dog very pretty”
Gow Hoe Sai Lay: “Good Dog/Great Dog”
I haven’t spoken Cantonese regularly in about 15 years, so I can’t think of a good word that means “gentle” that you would use for a dog. I’ll see if I can come up with something.
Ngo Hoe Leck: “I am very smart” “Ngo” is “I”. It is kind of a difficult word for Americans to say. The NG sound is similar to ours, but we don’t use it in the front of words, whereas they do in Cantonese. You can always just drop it, they often do, and just say 'O. That isn’t a hard “O” sound. It is kind of between the AW in Law and a long O. You could also just leave it off and say “How Leck”, while pointing at yourself.
Ngo Sick Jong Mun: “I know Chinese” The O in “Jong” is close to a long O (like in boat)
Ngo Sick Gwong Dong Waa: “I know Cantonese” Gwong pretty much rhymes with long and Dong has a long O again, like in Boat.
I’m not using a standard romanization system here to try to make it easier to read for you. Let me know if you have any pronunciation questions.
As I mentioned in passing above, Cantonese uses tones as part of the pronunciation, so you won’t exactly sound like a native, but usually Chinese speaking people are happy when Gwai-louhs at least make an effort, so I am sure they will be thrilled.