Here's a breakdown:
* Hallo is the greeting, equivalent to "hello" in English.
* Hoe means "how."
* gaat is the third-person singular present tense of the verb "gaan" (to go).
* het is the neuter pronoun "it," referring to the state of being.
So, the full phrase literally translates to "Hello, how goes it?"
However, in everyday conversation, it's a standard greeting and understood to mean "Hello, how are you?"