“Agradecer a” vs “Agradecer por” in Portuguese: Thanking Someone or For Something

Introduction

Mastering the difference between agradecer a and agradecer por is essential for sounding natural in Brazilian Portuguese. Both express gratitude, but they answer different questions: who you thank and what you are thankful for. This article explains the grammar, gives clear examples, and offers cultural notes to help English-speaking learners use these constructions confidently.

Basic meaning: agradecer a vs agradecer por

Agradecer a focuses on the person or entity who receives the thanks. It answers the question quem — who do you thank. Use agradecer a when you mention the recipient of gratitude, often followed by a name, pronoun, or a noun phrase.

Agradecer por focuses on the reason, the cause, or the thing you are thankful for. It answers the question por quê or por que — why are you thanking. Use agradecer por when you mention a gift, an action, a favor, or an experience.

Structure and verbs: direct and indirect objects

Portuguese often distinguishes between direct and indirect objects with prepositions. The verb agradecer can take a direct object without a preposition in some contexts, but the most common and clear patterns are:

1) Agradecer a + indirect object (person or entity).
2) Agradecer por + reason (noun, clause, infinitive).

Examples show these patterns in natural Brazilian Portuguese sentences below.

Using agradecer a: thanking someone

Use agradecer a when explicitly stating who receives the thanks. Common pronouns and names appear after the preposition a. Note that personal pronouns after a can trigger clitic pronouns or tonic forms depending on emphasis and formality.

Examples:

Quero agradecer a Maria pelo apoio.
Vou agradecer ao professor no final da aula.
Eles agradeceram a nós pela ajuda. (more natural: Eles nos agradeceram pela ajuda)

Observe that a + o / a contracts to ao / à, so:

Agradeço ao João.
Agradeço à equipe pelo esforço. (here mixing agradecer a with the reason will often use por; see notes later)

Using agradecer por: thanking for something

Use agradecer por to specify the reason for gratitude. The object after por can be a noun, a clause introduced by ter or por ter, an infinitive, or even a gerund in casual speech.

Examples:

Agradeço por toda a ajuda.
Ela agradeceu por ter recebido a bolsa de estudos.
Agradecemos por ter vindo hoje.

In everyday Brazilian Portuguese people sometimes use agradecer por followed by an infinitive to express gratitude for an action, for example: Agradeço por ter vindo. Both grammar and usage accept this form.

Combining both: thanking someone for something

Often you want to mention both the person you thank and the reason. In these cases, Brazilian Portuguese commonly uses agradecer a for the person and por for the reason in the same sentence. There are two frequent word orders:

1) Agradecer a [pessoa] por [motivo].
2) Agradecer por [motivo] a [pessoa] (less common but possible).

Examples:

Quero agradecer a você por toda a paciência.
Agradecemos ao time por o excelente trabalho.
Ela agradeceu ao marido por comprar os ingressos.

Note the contraction ao when masculine: a + o -> ao. For feminine nouns, use à only if the definite article is required: agradecer à professora por…; often articles are omitted: agradecer a professora por…

Pronouns: clitic and tonic forms

When you use pronouns instead of names, Brazilian Portuguese prefers clitic pronouns (me, te, lhe, nos, lhes) in formal written speech and tonic pronouns (mim, você, ele/ela) with prepositions in spoken or emphatic contexts. With agradecer a you usually use an indirect object pronoun before the verb or a tonic pronoun after the preposition.

Examples:

Eu agradeço a você. (tonic form after the preposition)
Eu lhe agradeço. (clitic indirect object pronoun before the verb; more formal)
Ela nos agradeceu pela paciência.

Avoid using me after a without emphasis: agradecer a mim is possible for emphasis: Ele agradeceu a mim por ter ajudado.

Infinitives, clauses, and verbs after por

After agradecer por you can use different structures depending on what you want to highlight:

– Noun: Agradeço por sua ajuda.
– Infinitive: Agradeço por ter ajudado ou Agradeço por ajudar (both used; ter ajudado emphasizes completed action).
– Subordinate clause: Agradeço por você ter vindo.

Examples:

Agradecemos por o presente.
Agradeço por ter recebido o convite.
Agradeço por você ter me avisado.

Note that in spoken Brazilian Portuguese, speakers sometimes shorten por to pra. While common in speech and informal writing, pra is colloquial and should be avoided in formal contexts.

When to use agradecer sem preposição

In some contexts, agradecer can be used without a preposition when followed directly by a noun phrase, but this is less common and can sound awkward. Native speakers often prefer explicit prepositions to avoid ambiguity. For clarity, especially for learners, stick to agradecer a for people and agradecer por for reasons.

Passive and reflexive uses

Agradecer also appears in passive or reflexive-like constructions where the focus shifts. For example, using se with agradecer or the passive voice with ser + agradecido changes emphasis but doesn’t alter the prepositional choice for reasons.

Examples:

Fui agradecido pela ajuda. (I was thanked for the help — literal passive, less common)
A gente se agradeceu mutuamente. (We thanked each other; here se indicates reciprocal action)

Even in passive or reflexive constructions, use por to indicate the reason: Ele foi agradecido por todos.

Common mistakes and how to avoid them

Mistake 1: Using agradecer por when naming the person. Incorrect: Agradeço por Maria. Correct: Agradeço a Maria or Eu agradeço à Maria por…
Mistake 2: Using agradecer a for a reason without a person. Incorrect: Agradeço a pelo presente. Correct: Agradeço por o presente or Agradeço pelo presente.
Mistake 3: Omitting prepositions and creating ambiguity. For clarity, use agradecer a with people and agradecer por with reasons.

Examples contrasting correct and incorrect forms:

Incorrect: Agradeço a pela ajuda.
Correct: Agradeço pela ajuda. (pela = por + a, common form when the reason noun requires an article)

Incorrect: Agradeço por João.
Correct: Agradeço a João.

Short forms and contractions: por + article

When the reason includes a definite article, por contracts: por + o -> pelo; por + a -> pela; por + os -> pelos; por + as -> pelas. These contractions are very common in Brazilian Portuguese and should be used naturally.

Examples:

Agradeço pelo convite.
Ela agradeceu pela oportunidade.
Agradecemos pelos conselhos.

Politeness and cultural notes

Brazilian Portuguese speakers often express gratitude frequently and warmly. Politeness formulas include obrigado/obrigada as well as agradecer constructions. Use agradecer a when formally addressing someone you thank explicitly, like a teacher, manager, or older relative. Using agradecer por with detailed reasons shows thoughtfulness and appreciation for specific gestures.

Cultural examples:

In a work email: Quero agradecer ao time pela dedicação. (formal and professional)
In casual conversation: Valeu, obrigada! (informal thanks; note obrigado/obrigada agree with speaker gender)

When thanking large groups or institutions, both patterns work: Agradecemos à empresa pela parceria or Agradecemos por toda a parceria — the first emphasizes the entity, the second emphasizes the reason.

Examples in longer sentences: natural contexts

Below are full-sentence examples that show how Brazilians naturally combine these expressions in emails, conversations, and formal thanks.

Email to a professor:
Prezada Professora,
Quero agradecer a senhora por todo o apoio durante o semestre.
Atenciosamente.

Thanking a friend for help with a move:
Obrigada por me ajudar ontem! Também quero agradecer a você por carregar as caixas.

Public speech or toast:
Agradeço à organização por tornar este evento possível e a todos os voluntários por seu tempo.

Quick reference chart

When to use which form — short guide:

Use agradecer a when naming the person or entity you thank.
Use agradecer por when specifying the reason, gift, favor, or action.
Use both together to specify who and why: agradecer a [pessoa] por [motivo].

Conclusion

Understanding the difference between agradecer a and agradecer por helps you sound natural and precise in Brazilian Portuguese. Remember: agradecer a names who receives the thanks; agradecer por explains the reason. Use contractions like ao and pelo where appropriate, and prefer clitic pronouns for formality or tonic pronouns for emphasis. With practice, these structures will become second nature in both spoken and written contexts.