How to tell a personal vs. impersonal sentence?

Question

I read an example that said this sentence was personal: Его ослепила молния and this one impersonal: Его ослепило молнией

To me they both mean "The lightning blinded him." I don't really understand how to tell the difference between a personal and impersonal sentence. Is it something like "he was blinded by the lightning" in the instrumental case as opposed to "the lightening blinded him" in nominative? When writing my own sentences what is the easiest way to know whether it is a personal or impersonal construction?

Answer 1

Usage and semantics:

Being a native Russian speaker, I'd say that "его ослепила молния" and "его ослепило молнией" are semantically equivalent. But until you know Russian very well, you should generally avoid impersonal sentences, because it is easy to make a mistake:

• Его ослепило молнией - correct
• Его дёрнуло/ударило током - correct
• Его убило пулей - correct
• Его убило шальной пулей - correct
• Его разбило параличом - correct
• Корабль снесло ветром - correct
• Его укусило собакой - incorrect
• Его воскресило дефибриллятором - incorrect
• Его вылечило от туберкулёза горным воздухом - incorrect

Generally, impersonal sentences of this kind are used when inanimate object performs some action, and the action was not purposeful. You can say "Джона убило пулей" if he was a soldier, and enemy soldier shot to the general direction of his military unit, but not if the shooter had a purpose to kill John personally.

Finally, ток, when it means electric current, requires impersonal sentence. You cannot say "меня ударил ток" or "меня дёрнул ток".

Grammar:

In personal sentences:

• The subject is in nominative case
• The object is usually in accusative case (not genitive), unless there is a preposition (however, there are exceptions from this rule: Вася владел русским языком)
• The verb has the same gender/number as the object

In impersonal sentences of this kind:

• The subject is in instrumental case
• The object is in accusative case (not genitive)
• The verb is in singular neuter

Answer 2

Dima is right, I would like to expand the answer a bit.

The predicate agrees with the subject in person, number, and (in the past tense) in gender. Naturally, the subject must be in the Nominative case.

The first example, Его ослепила молния, is definitely personal, because the Feminine gender of the predicate explicitly points to молния being the subject, there is no other Feminine noun in the sentence, and молния is in the Nominative case.

The second example, Его ослепило молнией must at once draw you attention by several obvious differences from the first one: 1. there in no noun or pronoun in the Nominative case in that sentence (no explicit candidate for the role of the subject); 2. the predicate is in Neuter gender, but there are no Neuter gender nouns (and no infinitives which also make predicate take the Neuter gender form). That means the Neuter gender subject is omitted, and there is only one such subject, оно ("it"), it is always omitted in Russian, and this is very typical of an impersonal sentence.

Answer 3

Personal sentences have a subject. Impersonal sentences do not. In the sentence "Его ослепила молния", "молния" is the subject (nominative case), while "его" is the object (genitive case). On the other hand, in the sentence "Его ослепило молнией", "молнией" is in the instrumental case, and "его" is still in genitive. So neither can be the subject.

Answer 4

You are confused because there is no exact translation for его ослепило молнией into English. It should be it blinded him by the lightning with it being a dummy pronoun as in it is raining. A good impersonal sentence example would be it is getting dark = темнеет. In English you use a dummy pronoun for the subject, in Russian you omit it.

There is also a slightly different type of sentence that lacks a subject -- a zero person construction. In impersonal sentences the implied subject is a weather or other natural force causing the action, whereas zero person implies a person: they say miracles are past = говорят, что чудес больше не бывает. In English the difference here is the dummy pronoun, it is they or one as opposed to it, in Russian you still omit it.

So basically when you cannot find an explicit actor in the sentence, it is either impersonal or zero-person construction.