An appointment can be for a meeting, but they aren't really interchangeable. A meeting is a group getting together for a specific purpose/discussion. An appointment is a block of time set aside to do something, usually with another person, but it doesn't have to be a meeting, and even when it is, you might say that your appointment is a meeting but you wouldn't say that your meeting is an appointment.
Or if you did, those sentences would mean different things.
Why is the prefix "ge-" not used with "vergessen"? Is there a rule, or is it just something that has to be memorized?
There is a rule. Words with the prefix ver- do not take on the ge- when in past tense.
Sie haben den Wald verlassen.
Ich habe meinen Roman veröffentlicht.
Michael hat den Termin vergessen..
The larger rule is that non-emphasized prefixes (ver-, ent-, be-, zer-, er-, …) a) don't split off ("ich kaufe ein" vs "ich verkaufe"), and b) won't get a "ge-" as participle II.
"He has forgotten the date" is got refused! But Termin can even take date as translation. At least, that's what Langenscheidt on the Internet is making clear: 1."einer Termin festsetzen" =fix or agree for a date, for doing something with somebody.2."zum nachstmöglichen Termin" =as the earliest possible date, as soon as possible.3."Termin für Manuskriptabgabe" =date for delivery (of manuscript). Thanks to Langenscheidt I am going to report...
I agree with you. Other languge courses taught me that Termin can mean a date, in that sense too. Good luck reporting it. I give up trying.
Also it has not accepted the past participle "forgot"... American English only here?
The English sentence is not in perfect tense. Please fix in order to match this unit.
"He has forgotten the appointment" is the only acceptible answer under this unit: "Perfect Tense"
The lesson is covering the German perfect, which incidentally can be translated as either English present perfect or simple past.
The distinction in meaning that exists in English does not really exist in German, making either an acceptable answer.
'Forgot' as the past participle of 'forget' is uncommon and possibly a bit archaic, but not strictly "wrong" as such.
Is it ever "Er hat den Termin vergisst" ?
What's the rule for whether the verb ending is like "er hat es verkauft" or like "er hat es vergessen" ?
No, "Er hat den Termin vergisst" would be like saying "He has forgets the appointment."
You never have two declined forms of a verb in the same sentence, and in your example, hat and vergisst are both declined. When there are two verbs in a sentence, the first auxillary verb (hat, had) is declined, and the second one is either an infinitive or a participle form. Forgotten and vergessen are both past participles, which both also happen to be the same as the infinitive.
As for whether a participle has an -en or -t ending, participles of irregular verbs ("strong" verbs) end in -en, and participles of regular verbs end in -t. ("Weak" verbs.)
A quick test is that, if the vowel changes between the first person singular and the third person singular, then it's an irregular verb.
So "vergesse, vergisst" -> irregular -> hat vergessen.
But "verkaufe, verkauft" -> regular -> hat verkauft.
The infinitive has the same vowel as the first person singular, so many people use that instead: Vergessen, vergisst, hat vergessen Verkaufen, verkauft, hast verkauft.
Termin includes meeting in its list of meanings, so why is he forgot the meeting not accepted; plus he forgot the deadline was given as the correct answer. Confusing or what?
Can't Termin also mean term, as in a specific or scientific term? (i.e. "black hole")