The Portuguese verb HAVER causes a lot of confusion.
If you look at the definition it's:
But listening in on its actual use, you'll find that it's used just like the verb, TER. And then there's the fact that it appears to be yet another verb to express TO BE -- in a language that already has the two prominent verbs SER & ESTAR.
And if you start investigating this whole mess you will soon run into long and detailed explanations (from linguists) about the subtle differences and uses of one vs. the other. More interesting (to me, at least) is how Brazilian actually use the Portuguese verb HAVER in conversation.
Though you will hear HAVER used almost interchangeably with the verb TER, they actually use it in specific ways.
*Notice that haver is used in the PRESENT TENSE to talk about the PAST! That's because you are literally saying, there are x anos since y is happening. No past conjugation needed 😉
Now let's see what happens when we do conjugate haver in the past tense.
*The grammatically correct way to say this is, O que é que houve? but conversational Portuguese has dropped the 'é'.
In this case houve (the simple past tense) translates to there was / there were.
You will often hear people say for example, não há rather than não tem. In cases like this haver and ter are literally interchangeable.
You'll also see haver used to talk about the future, but only in magazine articles or news reports/ Like this:
But you won't hear this in daily conversation.
Do not waste your time memorizing the bizarre conjugations of this verb. But make sure you can use and pronounce these two versions.