Mão vs. mano
While the Portuguese words mão and mano may sound similar to an English speaker, they have completely different meanings and uses. Mão refers to a body part, while mano is an informal term of address or reference for a person.
Mão
A1The word mão is a feminine noun that means hand, the part of the body at the end of the arm. It is a standard, common word used in many literal and idiomatic expressions.
Por favor, lave a sua mão antes do jantar.
(Please, wash your hand before dinner.)
Você pode me dar uma mão com estas caixas pesadas?
(Can you give me a hand with these heavy boxes?)
O artesão fez esta cadeira à mão.
(The artisan made this chair by hand.)
Cuidado, esta é uma rua de mão dupla.
(Be careful, this is a two-way street.)
Ele teve que abrir mão de suas férias para trabalhar no projeto.
(He had to give up his vacation to work on the project.)
Eu escrevo com a mão esquerda.
(I write with my left hand.)
Mano
B1The word mano is an informal masculine noun, a slang term for brother. It is a shortened version of irmão. It is also widely used to refer to a close male friend, similar to bro or dude in English.
E aí, mano, tudo bem com você?
(Hey bro, is everything alright with you?)
Meu mano mais velho me ensinou a dirigir.
(My older brother taught me how to drive.)
Mano, você não vai acreditar no que aconteceu hoje.
(Dude, you won't believe what happened today.)
Vou sair com os manos para jogar bola.
(I'm going out with the guys to play ball.)
Fica tranquilo, mano, eu te ajudo com isso.
(Don't worry, bro, I'll help you with that.)
A namorada do meu mano é muito simpática.
(My brother's girlfriend is very nice.)
Summary
In summary, the key difference is that mão means hand and is a standard part of the language used in all contexts. In contrast, mano is informal slang for brother or bro/dude and is primarily used in casual conversation. The two words are never interchangeable.