Moderator edit: This thread was split from another but it need not revolve around the topics and examples mentioned in the first couple of posts. Please feel free to tell us how you express aspects in your languages and - if you are unfamilliar with the concept (which is the case with a high probability) - do not hesitate to ask for clarification. 
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I just did a search for "perfective verbs", and this is what I immediately saw:
English-Belarusian Dictionaries: Grammar: Perfective VerbsEnglish-Belarusian Dictionary provides a searchable database and some older English-Belarusian word lists.
Czech verbs - aspect (vid), perfective and imperfective verbsPerfective verbs are often formed by adding a prefix, such as s-, za-,
Perfective verbs of motionThe normal Perfective partner of идтО/ходОть, Ѕхать/Ѕздить, летЅть/лет¬ть is formed with the prefix по- on the One-way verb.
If you wish you can start a thread in the English forum about this term, but I believe you will find out that most native speakers of English will be highly confused by the terms "perfective" and "durative". I'm not saying that they do not exist, but I have never seen them used, and they are really not at all helpful for English.
Gaer
***
I just did a search for "perfective verbs", and this is what I immediately saw:
English-Belarusian Dictionaries: Grammar: Perfective VerbsEnglish-Belarusian Dictionary provides a searchable database and some older English-Belarusian word lists.
Czech verbs - aspect (vid), perfective and imperfective verbsPerfective verbs are often formed by adding a prefix, such as s-, za-,
Perfective verbs of motionThe normal Perfective partner of идтО/ходОть, Ѕхать/Ѕздить, летЅть/лет¬ть is formed with the prefix по- on the One-way verb.
If you wish you can start a thread in the English forum about this term, but I believe you will find out that most native speakers of English will be highly confused by the terms "perfective" and "durative". I'm not saying that they do not exist, but I have never seen them used, and they are really not at all helpful for English.
Gaer