Among ancient languages, there are certain traits of aggluttination in Hittite (especially in its verbs of mi-class).
If you are interested in living languages, then one of the possible suggestions would be verbs of the regular -ar or -er types in modern Swedish. The -ar- type is a type of verbs of regular declention taking, like the rest of regular Swedish verbs, a similar ending (here, -ar) for all and any personal forms in Present.
Consider e.g. the verb att svara (to answer):
1. jag svarar vi svarar
2. du svarar ni svarar
3. hen svarar de [dom] svarar
NB: hen is a new coinage, presumably a calque from the Finnish hän. Both new Swedish and the Finnish words mean the same: (s)he. The actual and more exact gender-specific pronouns in Swedish are hon for 'she' and han for 'he'.
Now let's make a Past Tense form:
1. jag svarade vi svarade
2. du svarade ni svarade
3. hen svarade de [dom] svarade
Finally, the Passive Form would be
svaras (it is answered = ´svara+ s ') and svarades (it was answered/answering = 'svara+*de*+s').
But there is more of agglunativity in Swedish nouns, though:-)
Consider e.g. the word eld (fire).
The plural form is eld+ar (yes, unlike -or, the -er and -ar endings are applicable for nouns and verbs, although the adjectives have a different plural - or, actually, emphasised - form).
The postpositional definite article is -na; hence, 'the fires' will be
eld+ar+na => eldarna
UPD: the -na here conveys the meaning of both plurality and definitiveness, and can be divided into -n- (postpositive plural definite marker) + a (emphasised form of a noun applicable in plural only).
So, this form of word can be further structured as eld+ar+n+a => eldarna
Morover, there is a common Germanic survival of the Genitive case, which is - suprisingly! - s.
Hence, 'of [the] fires' (like in 'light of [the] fires') will be
[[eld+ar+n+a+s] ljus] => eldarnas ljus