Existential constructions
An existential construction is like the English verb “there to be” in the sentence “There are many countries”.
Possessive existential: uses the verb “to have” like in French “il y a” (lit. it there has”, or Brazilian Portuguese “não tem jeito” (there’s no way, lit. not has way), or in Serbo-Croatian, and many southeast Asian and Chinese languages, and Swahili.
Copula existential: uses the verb “to be” or an equivalent, like English “there is/are”. Most Slavic, Baltic, Uralic, Mongolic and Indo-Iranian languages work like this. Also, Korean, many Germanic languages, Iraqi Arabic, Kannada (Dravidian, in India), Mixtec languages, Italian, Greek, Armenian, Georgian.
Existential verb: Portuguese, Spanish, Sardinian, Catalan, Occitan, Yoruba, Malay-Indonesian have a special existential verb. For example in Portuguese is “haver” and Spanish “haber”. In Portuguese (and only in he formal register in Brazilian variety) there’s “há um problema” (there is a problem) in which “haver” means exactely “there to be” and nothing else (although it’s also an auxiliary verb with a multitude of grammatical functions). Etymologically “haver/haber” meant “to have” (btw, despite the similarity with English, the verbs are not related).
Other verb: Dutch, German, Swedish, Japanese, Hausa and Somali have another verb which is used for this meaning. In German is “gibt” (give), and in Swedish is “finnas” (to find).
Adjective: for most Tukic languages it’s an adjective “var” (or some related word), which in fact works like a particle.
Locative existential: it appears in Maori, Maltese, Tunisian and Lybian Arabic, as a place adverb. lt co-occurs with other types like in English “there”, French “y”, Catalan “hi”, Italian “ci”, and there’s also a locative preffix in Swahili.
Prepositional pronouns: a pronoun fused with a preposition, it occurs as “fi” (with it/him) in some Arabic languages/dialects.
If you know the languages left in Blank please write in the comments.