The article focuses on a special use of the Russian perfective past, which is virtually similar to a progressive one: it is illustrated by examples like Smotri, samolët poletel ‘Look, a plane is flying’. I show that, in fact, this use, though characteristic of a small group of motion predicates, is a part of the whole class of uses that express the partial access of the speaker to the situation (‘partial observation’): in this particular case, the speaker can only observe the middle phase of the situation, while the initial phase remains invisible. The use of perfective aspect denotes the fact that the observation period is short and represents the starting point of the observation as if it were the starting point of the situation itself. Similar phenomena are found both in the class of resultative constructions and in other construction classes: the speaker cannot observe a part of the situation and describes only the observable phase as if it was the only one. At the same time, the class of the partial observation readings is heterogeneous. First, some of them allow temporal clauses with the simultaneity meaning and other contexts, characteristic of progressive constructions, while others are incompatible with those mechanisms. Second, only some of those constructions are lexically productive, while others, like, for instance, our progressive-like constructions, characterize a small group of lexemes. I conclude that our use does not, in fact, demonstrate combinatorial properties, characteristic of progressives, thus, no nonstandard progressive past tense use is observed. The meaning of a past event is retained in the construction under analysis, and what is nonstandard is the fact that the speaker describes in the ‘online’ mode those events that have just taken place before the speech act (this use can be called ‘immediate comment’).