Understanding of human language
>All Pokémon in the Pokémon anime, with no exceptions, can understand human speech. Moreover, judging, for instance, from Larvitar in Hatch Me If You Can, they are able to do this immediately after hatching, without having to learn.
>The anime generally does not focus on language problems, so as a result, there is some confusion about Pokémon language and the ability of Pokémon to understand humans. Although it is obvious that all Pokémon can understand each other, Meowth in the episode Go West Young Meowth once mentions Meowth language, and Jessie in Who's Flying Now? mentions Chimecho language, so it is not clear whether there is a common Pokémon language, or every species has its own.
>As far as human language is concerned, Meowth in the same episode was shown learning pronunciation, not the language itself, what implies that all Pokémon have innate knowledge of human language, so they can understand human speech, and only have to learn how to pronounce its sounds, or be able to establish telepathic contacts to speak. Despite this, Misty in Whichever Way the Wind Blows once asked Meowth to translate her words to other Pokémon, and May taught her Bulbasaur the meaning of the word town in Grass Hysteria!. Therefore, this ability of Pokémon is not well-defined in anime canon.
>Although every Pokémon in the anime can understand human speech, very few can talk, although many legendary Pokémon can. In most cases though, talking Pokémon speak through telepathy.
>- Meowth is the most famous talking Pokémon, and the one that makes the most appearances. His clone in Mewtwo Strikes Back and Mewtwo Returns, however, cannot speak, the reason being Meowth wasn't born knowing how to speak human language: he learned how to speak human language.
>- In Island of the Giant Pokémon, Ash's and Team Rocket's Pokémon can speak due to most of the episode focusing at them (although this is done through subtitles in the Japanese version and several of the dub versions). This prevents the difficulty of understanding Pokémon saying only the syllables of their names.
>- A Tentacruel in the episode Tentacool and Tentacruel speaks through Meowth via telepathy.
>- A Gastly in The Ghost of Maiden's Peak has the ability to talk.
>- Santa Claus's Lapras in Holiday Hi-Jynx has the ability to talk telepathically.
>- Both Mewtwo seen in the anime can talk via telepathy.
>- The Gastly and Haunter in the episode A Shipful of Shivers speak through Meowth via telepathy.
>- The Lugia in The Power of One also speaks via telepathy.
>- A Slowking in The Power of One can also talk without telepathy. Presumably this is because of its wisdom.
>- Entei can talk in Spell of the Unown. However, this Pokémon is the embodiment of Molly's wishes, so therefore it is not currently known if Entei itself can speak.
>- Ash's Larvitar in Address Unown was speaking when Ash and his friends entered its mind.
>- Max's Ralts in Do I Hear a Ralts? talked to Max as it teleported away via telepathy.
>- Deoxys from Pokémon Ranger - Deoxys' Crisis! (Part 1) and (Part 2) spoke through Meowth telepathically.
>- Jirachi can talk via telepathy in Jirachi: Wish Maker.
>- Lucario can talk in Lucario and the Mystery of Mew via telepathy.
>- Manaphy can talk without using telepathy in Pokémon Ranger and the Temple of the Sea, although it can only say a few words (such as "happy" and "I love you") as it is still a baby.
>- Chatot can repeat human words.
>- Darkrai occasionally speaks in The Rise of Darkrai.
>- Shaymin can speak telepathically in Giratina and the Sky Warrior.
>- Arceus is able to speak human language in Arceus and the Jewel of Life.
>- A Snover from the Ice Palace can mysteriously talk in Pikachu's Ice Adventure.
>- Zorua can speak telepathically in Zoroark: Master of Illusions.
>- A Yamask speaks through Cilan in A Night in the Nacrene City Museum! while possessing him with its mask.
>- Zekrom and Reshiram are able to speak telepathically in White—Victini and Zekrom and Black—Victini and Reshiram.
>- Kyurem and the Swords of Justice, including Keldeo, are able to speak via telepathy in Kyurem VS. The Sword of Justice.
>- The members of the Genesect Army in Genesect and the Legend Awakened are able to speak via telepathy.
>- In The Island of Illusions!, a Zoroark is able to talk by changing its form into a Nurse Joy.
>- Diancie, several Carbink, Xerneas, and Yveltal can speak telepathically in Diancie and the Cocoon of Destruction.
>- In The Cave of Mirrors!, the Mirror World counterpart of Meowth appeared, which, like his regular world counterpart, is able to talk.