Venire always requires essere as auxiliary, and can be an auxiliary in its own right, in passive sentences.

Movement verbs have a different Past tense form. Andare, venire etc. (Some of them don't sound like movement words but they are considered as such).

It's like "I am gone" instead of "I went". I guess this was the way it was in old english too.

You might want to download the free app Italian Verbs, available through PlayStore. It gives all the conjugations and is very easy to use.

same in here, totally lost myself in the clitics and this section.... :=(

I've had five separate stabs at learning Italian here. Three times I reached clitics and threw up my hands in despair - I could not understand the rules behind how they worked. The 4th time I ploughed through regardless and completed the tree to the basic level. I'm now returning up and down the lessons and, once again, clitics makes me despair.

I know that additional reading outside of this site is essential to building on the knowledge gained here, but this area is so incredibly obtuse and frustrating.

Most verbs of motion require essere as the auxialiary instead of avere. Reflexive Italian verbs also require essere. Transitive Italian verbs require avere (transitive verbs can have direct objects, but they are not required: "I ate" "I ate apples".)

English in the long-ago past used "to be" in this way, but has replaced it with "to have" in almost every compound verb. Sometimes, though, past participles look more like adjectives or are actually replaced by adjectives, so that "to be" is still used as an "auxiliary". The best example of this is io sono morto which can be translated as "I am dead [adjective]" or "I have died [past participle]".

'I have come already here' doesn't make sense

già comes between sono and venuto:

Adverb Placement in Italian
Duolingo discussion by sandrabruck at: ** https://forum.duolingo.com/comment/2574748

The position of the adverb in Italian depends:

a) if it refers to a verb, an adjective, another adverb or a part of a sentence it's in front of them

• È una donna veramente simpatica. (it refers to the adjective "simpatica")
• Elza parla veramente male. (it refers to the adverb "male")
• Forse Simone vuole andare al teatro. (it refers to the rest of the sentence "simone vuole andare al teatro)

If it refers to a verb there are more possibilities:

b) in case of simple or compound verbs, infinitive or gerund it's placed after the verb.

• Simone parla lentamente. (simple verb)
• Ha parlato molto (compound verb)
• A me piace parlare rapidamente. (infinitive)
• Parlando molto ti stanchi presto. (gerund)

c) There are some exceptions (always referring to a verb) This exceptions stand in case of a compound verb between the auxiliary and the participle

• ancora (non l'ho ancora sentito)
• appena (stavo appena mangiando)
• già (l'ho già detto)
• quasi (ho quasi finito)
• mai (Non l´ho mai visto.)
• neanche (non me l'ho neanche immaginato)
• nemmeno (ho nemmeno sentito parlare di te)
• neppure (non ha neppure considerato la possibilità)
• **sempre (Frank ha sempre parlato con me)

d) Anche/pure and solamente/soltanto stand before the word they refer to.

• Anche il tuo amico Stefano ha chiamato ieri. (not only Stefan has called but also somebody else).
• Il tuo amico Stefano ha anche telefonato (he has not only called but also ... ...)

In English, we'd more likely say, "I have already been here before".

Duo's English sentence is unnatural and makes little sense, so don't worry about it, and try to forget it. It's bad English.

Because arrivato doesn't mean "come", it means "arrived". Related ideas, but not the same in this instance.

I I put venito and it accepted it It's still wrong. It's just irregular. Venuto is correct

That would be a correct answer too

You mean "If a women is speaking...". You cannot tell from the sentence whether it's a male or a female, man, woman or child, so "since" is the wrong word to use in English.

Adverb Placement in Italian
Duolingo discussion by sandrabruck at: ** https://forum.duolingo.com/comment/2574748

The position of the adverb in Italian depends:

a) if it refers to a verb, an adjective, another adverb or a part of a sentence it's in front of them

• È una donna veramente simpatica. (it refers to the adjective "simpatica")
• Elza parla veramente male. (it refers to the adverb "male")
• Forse Simone vuole andare al teatro. (it refers to the rest of the sentence "simone vuole andare al teatro)

If it refers to a verb there are more possibilities:
b) in case of simple or compound verbs, infinitive or gerund it's placed after the verb.

• Simone parla lentamente. (simple verb)
• Ha parlato molto (compound verb)
• A me piace parlare rapidamente. (infinitive)
• Parlando molto ti stanchi presto. (gerund)

c) There are some exceptions (always referring to a verb) This exceptions stand in case of a compound verb between the auxiliary and the participle

• ancora (non l'ho ancora sentito)
• appena (stavo appena mangiando)
• già (l'ho già detto)
• quasi (ho quasi finito)
• mai (Non l´ho mai visto.)
• neanche (non me l'ho neanche immaginato)
• nemmeno (ho nemmeno sentito parlare di te)
• neppure (non ha neppure considerato la possibilità)
• **sempre (Frank ha sempre parlato con me)

d) Anche/pure and solamente/soltanto stand before the word they refer to.

• Anche il tuo amico Stefano ha chiamato ieri. (not only Stefan has called but also somebody else).
• Il tuo amico Stefano ha anche telefonato (he has not only called but also ... ...)

If you wrote it exactly like that, Duo might have reacted to the word "gia" which lacks the accent, it should be "già".