Questions & Answers about Она кивнула, и я сразу всё понял.
Why is it кивнула and not just some basic dictionary form of the verb?
Кивнула is the past tense form of the verb, because the sentence describes something that already happened.
The dictionary form is кивнуть = to nod.
In Russian, past tense forms change for gender and number:
- кивнул = he nodded
- кивнула = she nodded
- кивнуло = it nodded
- кивнули = they nodded
Since the subject is она (she), the verb has to be кивнула.
Why does понял look different from кивнула?
For the same reason: Russian past tense agrees with the subject in gender and number.
Here, the subject is я (I), but Russian past tense still shows gender:
- я понял = I understood / I got it (male speaker)
- я поняла = I understood / I got it (female speaker)
So я сразу всё понял tells you the speaker is male. If the speaker were female, it would be:
Она кивнула, и я сразу всё поняла.
Why is она included? Couldn't Russian just omit it?