De thermometer meet mijn temperatuur vóór behandeling.

Meet is the present-tense form of meten, which means to measure.

So De thermometer meet mijn temperatuur means The thermometer measures my temperature. In English, depending on context, you might also translate it as is measuring.

The infinitive is meten. When Dutch forms the verb stem, it keeps the long vowel sound, so meten becomes meet.

That gives:

• ik meet
• jij meet
• hij/zij/het meet

It is not meett because the stem already ends in -t. Dutch does not add another t in forms like this.

Also, met is already a different word in Dutch: it means with.

Thermometer is a de-word in Dutch, so the correct article is de.

Unfortunately, noun gender in Dutch often has to be learned word by word. There is no simple rule that always tells you whether a noun takes de or het. So you learn it as de thermometer.

Dutch usually uses a possessive like mijn where English would also say my.

So:

• mijn temperatuur = my temperature

Dutch could theoretically say something like de temperatuur van mij, but that sounds unnatural here. Mijn temperatuur is the normal and idiomatic choice.

Both forms exist, but vóór with an accent is often used to make it clear that the meaning is before.

So here:

• vóór behandeling = before treatment

Without accents, voor can also mean for or in front of, so the accents help avoid confusion. In many texts, people leave the accents out if the meaning is already obvious, but using vóór is completely correct and often helpful.

Without an article, behandeling is being used in a more general or institutional way, a bit like English before treatment.

If you say vóór de behandeling, that usually sounds more like you mean one specific treatment: before the treatment.

So the difference is roughly:

• vóór behandeling = before treatment, in a general/clinical sense
• vóór de behandeling = before the treatment, a specific treatment

Behandeling usually means treatment, especially in a medical context. That is the most likely meaning here because the sentence mentions a thermometer and temperature.

The noun comes from the verb behandelen, which can also mean to treat, to handle, or to deal with, depending on context. But in this sentence, the medical meaning is the natural one.

Yes, it is understandable and correct, but it sounds a little formal or clinical, like something from a medical form, instruction, or app.

In everyday speech, many speakers would more likely say:

• De thermometer meet mijn temperatuur vóór de behandeling.

Adding de makes it sound more like a specific treatment. So the original sentence is fine, but it has a somewhat formal, label-like style.