Haver vs Ter: Existential and Auxiliary Uses
In European Portuguese, haver is used as an impersonal existential verb ("there is/are") and in some fixed time expressions. Ter has largely replaced haver as the compound-tense auxiliary in EP speech.
PortuStories Editorial
European Portuguese Grammar Guide
Haver as an existential verb is always third person singular, regardless of the number of things described.
Há um café perto daqui.
There is a café near here.
Havia muitas pessoas na praça.
There were many people in the square.
🇵🇹 European Portuguese
Há muitos alunos na turma.
🇧🇷 Brazilian Portuguese
Tem muitos alunos na turma.
BP uses ter as an existential; EP uses haver. Using "tem" existentially in EP sounds Brazilian.
In compound past tenses in spoken EP, ter has replaced haver: "tenho feito" not "hei feito". The haver auxiliary survives mainly in literary and formal written registers.
Hei de te dizer um dia.
I shall tell you one day.
Haver de + infinitive: volitional future, formal/literary register.
In everyday spoken EP: use há for "there is/are", and ter for possession and compound tenses. Never use ter existentially as done in BP.
From a PortuStories Story
Há muitos sítios bonitos em Portugal, mas há pouco tempo para os visitar todos.
There are many beautiful places in Portugal, but there is little time to visit them all.