Correct. It varies with species and with how well you know them. However using words does not necessarily reflect how you think. And one can think in multiple ways.
As an example: We have a large pack of working dogs on our farm who help with our livestock, keep down predators and assist us in tasks.
Our dogs have their own language. It is a mix of vocal and body language.
Our dogs understand a large part of our human language - English in our case.
We and the dogs also have a common pidgin language between us that is a mix of hand signs, body signs, vocalizations and English words. We have about 300 words in pidgin that we use back and forth between us. Some of the dogs use more words than others. Some rarely talk but clearly understand and every once in a while they will say something.
Yes, the dogs do speak some English words. Their vocal tracts aren't well suited to the task so they don't use very many spoken English words. More commonly they use signs or the pidgin words they can pronounce. But that's like us too - we can't pronounce some of the things in their language even though I can understand it when they same them.
When talking to us they use words to us like Yes and No to narrow down a conversation. They will tell us to Come, say the names of predators to alert us to issues, tell us if there is a problem with the livestock and often what the problem is. They have names for each other in their language and they know the names we use for them. They also have names for us. My name in their language sounds like rocks being gargled.
The dogs are heavy into pointing. We point with our hands and they understand that. They point with their muzzles and we understand that.
One of our dogs in particular has a very foul mouth. She cusses something awful when she's pissed about something. That's Katya. She is the smallest but she talks like a sailor as the saying goes...