please be careful with "spazieren" which differs in meaning from "spazieren gehen"
"spazieren gehen" means to go for a walk for pleasure, it means you are not in a hurry, and you are probably enjoying the landscape or the fresh air or just the movement as such. It is often a usable translation for "to walk" - when you are not walking to a definite place but just doing your customary walking.
"spazieren" on the other hand can mean you are walking in a silly and affected manner, and it is usually used in a situation which appears humorous in some way or other.
So "Ich spaziere mit meinem Vater" is nonsense. It has to be "Ich gehe mit meinem Vater spazieren."
You will meet "spazieren" in sentences like: "Der Pfau spazierte auf dem Dach herum" - It is a sight that makes you smile.
When you are walking with your father to the bus stop in order to catch the bus, you cannot use "spazieren gehen" In this case you would say: "Mein Vater und ich laufen zur Bushaltestelle" or "Ich gehe mit meinem Vater zur Bushaltestelle" .
Zchbaniel25 says, "spazieren" on the other hand can mean you are walking in a silly and affected manner, and it is usually used in a situation which appears humorous in some way or other."
just asked german friends about this, and they say there's no such usage. that it always means a leisurely walk.
According to Zchbaniel25, it is nonsense. At any rate, I don't think spazieren alone absolutely must be silly and affected, for example:
Genügend Zeit zum duschen, essen und ein wenig durch die Stadt zu spazieren. (this sentence was found here: http://velo-touren.ch/Griechenland.2007/de.htm)
Eines Morgens im Jahre 1998 spazierte Volkmar Wywiol am Strand von Dubai, ... (this sentence was found here: http://www.muhlenchemie.de/deutsch/unternehmen/engagement.html)
Even for herumspazieren, I'm not so sure it must be silly, for example:
Als Teddy an einem wunderschönen Wintermorgen im Wald herumspazierte, sah er ein Reh. (this sentence was found here: http://epomm.eu/docs/1887/weihnachtsfahrrad_deutsch.pdf)
Da das Wetter wieder mal gut war, konnten wir den ganzen Tag in einem Park herumspazieren und Karten spielen. (this sentence was found here (go to page 7): http://ngo.ch/australia_china0607/?id=2=de=7)
Wir spazierten bis Mitternacht, ohne Überzieher, herum; ... (this sentence was found here: http://www.rodoni.ch/busoni/bibliotechina/letteregerdaEN/gerdaTED2.html)
I'm not a native speaker (although I do speak German fluently), but these sentences don't appear to be in a silly context to me. Perhaps the implication of spazieren varies by dialect, Zchbaniel25 is in the far north of Germany, so it could be different elsewhere; an inflated amount of my examples come from Swiss URLS. Nevertheless, you're probably thinking I've got some nerve to question a native speaker.
Why has duo removed the possibility of free text fields within the "report"? I have reported that I think the German sentence to be unnatural, but had no chance to explain why. Though it is grammatically possible, you would only very seldom (if ever) hear "er spaziert mit seinem Vater", but ratehr "er geht mit seinem Vater spazieren".