If a writer were to say that a dog was "complaining," it is not a literally accurate depiction of what happened. The dog likely had been barking or yelping. "Complaining" is something that people do. Personifying animals only requires the use of verbs or descriptions that normally apply to just people. Likewise, a writer could say that a bird "commuted" to a certain rooftop daily.
Inanimate objects are defined as anything which do not move or live. A table is one example of an inanimate object. Not only does a table not perform human actions, it doesn't actively "do" anything. But if a writer were to say, "The table stubbornly held its ground as my knee whacked against it," or even that "The table attacked my knee as I walked past," the table suddenly becomes a character, one that can elicit an emotional response from a reader.
Abstractions are anything that is not tangible. You can't touch or interact with abstractions in a literal way. Emotions are all abstractions. "Love" and "anger" are two examples of abstractions. You cannot hold love in your hand, and you can't pick up a lump of anger. Personifying abstractions is a good technique in fiction to show that the concept has gained power. For example, a writer could say that that "love mocked me" or that "anger goaded me into action" to show that the two concepts have power over the narrator.
The weather can also be personified. Weather is often used by writers as a means of conveying emotions or overall themes through a non-living medium. For example, a writer could state that the "wind screamed past his ears" or that "the storm slept for two days." Because you're attributing these human traits (screaming and sleeping) to the weather, you're personifying them. A writer may wish to do this especially in a piece where the main character's major struggle is against nature.