In the online Oxford German Dictionary, there are properties enumerated beneath it.
For example 'hatte' has:
1.u. 3. Pers.Sg.Prät. v
What do those abbreviations and symbols mean?
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The Oxford German Dictionary must have a glossar and I'm sure, you will find all abbreviations there.
The verb "hatte" is:
Person = person
Singular = singular
Indikativ = indicative mood
Präteritum = a German tense similar (but not equal to) English past tense
Aktiv = active voice
Verb = verb (German genitive case of "das Verb" is "des Verbs" haben = to have