Medir means to measure — and crucially, it is also the everyday verb Brazilians use to state someone's height or an object's dimensions ("Ela mede 1,70 m"). It looks like a tame regular -ir verb, but it hides one of the nastiest little traps in the language: the first-person singular is meço, not "medo." Get the rest of the conjugation right and miss that single ç, and you'll sound like a learner every time you talk about your own height.
Why "meço" and not "medo"
Most -ir verbs that change in the first person are stem-changing (the vowel e→i, like in pedir → peço, or sentir → sinto). Medir does something different: the consonant changes. The stem-final d turns into ç before the first-person ending. This is the same d→ç swap you see in pedir (peço) and ouvir (ouço). The change appears only where the ending begins with the back vowels o or a — that is, in the first-person singular present (meço) and throughout the present subjunctive (meça, meças, meça, meçamos, meçam).
The reason is phonetic history, not arbitrary spelling. These verbs descend from Latin forms where a yod (a /j/ sound) palatalized the consonant only before back vowels. The "e" endings never triggered it, so the d survived there. You don't need the Latin to use the verb — but knowing the change is consonantal, not vocalic, stops you from over-applying the e→i pattern (you will not say "*mido").
Present indicative (presente do indicativo)
Note meço in the first person; every other form is regular.
| Pronoun | Form |
|---|---|
| eu | meço |
| tu/você | mede |
| ele/ela | mede |
| nós | medimos |
| vocês | medem |
| eles/elas | medem |
Eu meço um metro e oitenta.
I'm one metre eighty (tall).
Quanto você mede?
How tall are you?
A gente mede a febre com o termômetro do banheiro.
We take our temperature with the thermometer in the bathroom.
Preterite (pretérito perfeito) — fully regular
Good news: the preterite is completely regular, so there's no ç here.
| Pronoun | Form |
|---|---|
| eu | medi |
| tu/você | mediu |
| ele/ela | mediu |
| nós | medimos |
| vocês | mediram |
| eles/elas | mediram |
Ontem o médico mediu a minha pressão e disse que está ótima.
Yesterday the doctor measured my blood pressure and said it's great.
Eu medi a parede três vezes antes de comprar a estante.
I measured the wall three times before buying the bookshelf.
Imperfect (pretérito imperfeito) — regular
| Pronoun | Form |
|---|---|
| eu | media |
| tu/você | media |
| ele/ela | media |
| nós | medíamos |
| vocês | mediam |
| eles/elas | mediam |
Quando era criança, ela media a sombra para saber a hora.
As a child, she would measure the shadow to tell the time.
Future and conditional
Built on the full infinitive medir-, so both are regular.
| Pronoun | Futuro do presente | Futuro do pretérito (conditional) |
|---|---|---|
| eu | medirei | mediria |
| tu/você | medirá | mediria |
| ele/ela | medirá | mediria |
| nós | mediremos | mediríamos |
| vocês | medirão | mediriam |
| eles/elas | medirão | mediriam |
O engenheiro mediria de novo se houvesse tempo, mas a obra começa amanhã.
The engineer would measure again if there were time, but construction starts tomorrow.
In everyday Brazilian speech, the synthetic future is usually replaced by ir + infinitive: vou medir, vai medir. Reserve medirei for formal or written registers.
Subjunctive — the second place the ç appears
The present subjunctive is built from the meço stem, so the ç runs through the whole paradigm: meça, meças, meça, meçamos, meçam. The imperfect and future subjunctive, however, are built on the regular preterite stem medi-, so no ç.
| Pronoun | Presente do subjuntivo | Imperfeito do subjuntivo | Futuro do subjuntivo |
|---|---|---|---|
| eu | meça | medisse | medir |
| tu/você | meça | medisse | medir |
| ele/ela | meça | medisse | medir |
| nós | meçamos | medíssemos | medirmos |
| vocês | meçam | medissem | medirem |
| eles/elas | meçam | medissem | medirem |
É importante que você meça o ingrediente certinho, senão o bolo não cresce.
It's important that you measure the ingredient precisely, or the cake won't rise.
Quando você medir o quarto, me manda as medidas.
When you measure the room, send me the dimensions.
Imperative
Affirmative imperative for você borrows the subjunctive (meça); the negative is fully subjunctive.
| Pronoun | Affirmative | Negative |
|---|---|---|
| tu | mede | não meças |
| você | meça | não meça |
| nós | meçamos | não meçamos |
| vocês | meçam | não meçam |
Meça com calma, não tenha pressa.
Measure carefully, don't rush.
Non-finite forms
| Form | Value |
|---|---|
| Infinitivo | medir |
| Infinitivo pessoal (eu/ele) | medir |
| Infinitivo pessoal (nós) | medirmos |
| Infinitivo pessoal (vocês/eles) | medirem |
| Gerúndio | medindo |
| Particípio | medido |
Meaning and usage notes
- To measure (a dimension): medir a altura, a distância, a temperatura, a pressão.
- To be X tall / long: This is the high-frequency use English speakers forget. Portuguese uses medir where English uses to be ... tall. "Ele mede 1,80 m" = He is 1.80 m tall, not "*He measures...". The same applies to objects: "A mesa mede dois metros."
- Figurative: medir palavras (to choose one's words carefully), medir forças (to test one's strength against someone).
Common Mistakes
❌ Eu medo dois metros.
Incorrect — 'medo' means 'fear'; the 1sg of medir is 'meço'.
✅ Eu meço dois metros.
I'm two metres tall.
❌ Eu mido a janela.
Incorrect — overapplies the e→i pattern; medir changes d→ç, not e→i.
✅ Eu meço a janela.
I measure the window.
❌ Ele é dois metros de altura.
Incorrect — English calque; use 'medir' for height.
✅ Ele mede dois metros de altura.
He is two metres tall.
❌ Quando você medir... que eu medo certo.
Incorrect — future subj. 'medir' is fine, but present subj. is 'meça', not 'medo'.
✅ Espero que eu meça certo desta vez.
I hope I measure correctly this time.
The single most important thing to lock in: meço (present, 1sg) and meça (subjunctive) both carry the ç. Everything else uses a plain d.
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- Summary of Irregular Present Indicative FormsA2 — A consolidated reference table of the most common irregular Brazilian Portuguese verbs in the present indicative, grouped by the type of irregularity — suppletive stems, -g-/-ç- eu forms, -z- stems, and vowel-changing -ir verbs.
- Stem-Changing -ir VerbsA2 — The predictable e→i and o→u vowel shift in the eu form of many Brazilian Portuguese -ir verbs, and why it reappears throughout the subjunctive.
- PedirA1 — The irregular -ir verb 'pedir' (to ask for, request, order), including the d→ç change pedi/peço/peça, its object structure ('pedir algo a alguém'), and the crucial difference from 'perguntar'.
- SentirA1 — How to conjugate and use sentir (to feel, to sense, to be sorry) in Brazilian Portuguese — an -ir verb with the e→i stem change in the eu form (sinto) and throughout the present subjunctive.
- Spelling-Change VerbsA2 — Verbs that change spelling — but not sound — to protect a consonant's pronunciation across the conjugation.