"Amare" is the verb without any pronoun attached to it, generally used with an object. As Phil wrote, "amarsi" can have a reflexive meaning ("to love oneself"), or a reciprocal one ("to love each other"). Other verbs used commonly with a reciprocal meaning are "vedersi", "salutarsi", "incontrarsi", "abbracciarsi", "baciarsi", "stimarsi".

"Io ho incontrato Moshe" (verb + object).

"Io e Moshe ci siamo incontrati" (reciprocal value).

Sometimes the reflexive and reciprocal use can lead to ambiguities:

"Noi ci stimiamo" -> "We appreciate ourselves" or "We appreciate each other"?

You can avoid any reflexive meaning using extra words like "l'un altro" or "a vicenda":

"Noi ci stimiamo a vicenda".

Hi Moshe, good question!

You have a reflexive verb every time the subject does an action to himself/herself. Put differently, "They're washing themselves" is reflexive while "They're washing the dishes" is not. With the verbs "amare" and "amarsi," "Loro amano i cani" [they love dogs] would not be reflexive but "Loro si amano" [they love each other / they love themselves] would.

In the Passato Prossimo, non-reflexive verbs follow the following structure:

Subject + essere/avere + past participle

--> Io ho amato il pranzo [I loved the lunch]

With reflexive verbs, you always need to use the verb "essere" as your auxiliary verb:

Subject + reflexive particle + essere + past participle

--> Noi ci siamo amati [we loved each other]

All transitive verbs can have a reflexive form. However, that's not true for intransitive verbs -- in fact, they're never reflexive. A transitive verb like "to hug" can be used as "We hug them" or as "we hug each other" (transitive). An intransitive verb like "to walk" wouldn't have the reflexive option [we walk each other? would't make sense].

Hope this helps,

Federico

If you mean "love each other" or "love oneself," we have to use the reflexive -- it's not like in English, where reflexive is understood.

Il passato prossimo di "amarsi" si forma con essere. La particella deve concordare.

Yes, any verb can be reflexive if the object is the same as the subject.