Eu tenho saudade do mar.

Yes. Portuguese often leaves out subject pronouns when the verb form already makes the subject clear.

• tenho = I have
• so Tenho saudade do mar is perfectly natural

Using eu can add:

• emphasis
• contrast
• clarity

For example, Eu tenho saudade do mar, mas ele não puts extra focus on I.

Tenho is the first-person singular present tense of ter (to have).

So:

• eu tenho = I have
• você tem = you have
• ele/ela tem = he/she has

In this sentence, it expresses a present feeling: I have / I feel saudade of the sea.

Because Portuguese usually expresses this idea with a noun phrase, not a single verb.

The key word is saudade, which is a noun. So Portuguese often says things like:

• ter saudade de = literally to have saudade of
• estar com saudade de = to be with saudade of
• sentir saudade de = to feel saudade for

English uses I miss..., but Portuguese often builds the idea differently.

Saudade is one of those words that does not match English perfectly.

It can mean a feeling of:

• missing someone or something
• longing
• emotional absence
• nostalgia, depending on context

So in Eu tenho saudade do mar, the feeling is not just the sea is absent. It often suggests an emotional longing for it.

That is why saudade feels a little richer than a simple word-for-word miss.

Because saudade normally takes the preposition de:

• saudade de alguém
• saudade de alguma coisa

Also, mar is normally masculine:

• o mar = the sea

When de + o come together, they contract:

• de + o = do

So:

• saudade do mar = saudade de o mar → contracted to do mar

In this sentence, do mar is the natural choice.

Portuguese very often uses an article with common nouns like mar when referring to something specific or conceptually definite:

• o mar
• a praia
• o campo

So saudade do mar sounds natural, while saudade de mar sounds incomplete or unusual in normal speech.

But the article is not used in every case after saudade de. For example:

• saudade de você
• saudade de casa
• saudade da minha cidade

It depends on the noun and the structure.

Yes. All of these are correct:

• Tenho saudade do mar
• Estou com saudade do mar
• Sinto saudade do mar

They are very close in meaning, but there can be slight differences in feel:

• tenho saudade: very common, neutral
• estou com saudade: very common in Brazil; often feels a little more immediate or current
• sinto saudade: also correct, sometimes a bit more expressive or literary

In everyday Brazilian Portuguese, estou com saudade is especially common.

Yes, you can say saudades in some contexts, but saudade in the singular is completely normal here.

• Tenho saudade do mar sounds natural and standard.
• Tenho saudades do mar is possible, but it is less neutral in this sentence.

The plural saudades is especially common in expressions like:

• Mando saudades.
• Muitas saudades.
• Saudades de você.

So for this sentence, singular is the most straightforward choice.

Yes. A very common alternative is sentir falta de:

• Sinto falta do mar.

This is often closer to a plain English I miss the sea.

The difference in feel is roughly this:

• saudade often sounds more emotional, nostalgic, or affectionate
• falta can sound a bit more direct: something is missing from your life or experience

In many contexts, though, both are natural and correct.

A rough Brazilian pronunciation is:

eh-ooh TEN-yoo sow-DAH-jee doo mah(r)

A few helpful notes:

• eu sounds roughly like eh-ooh blended together
• tenho has the nh sound, like ny in canyon
• saudade is often pronounced something like sow-DAH-jee in many Brazilian accents
• do often sounds closer to doo
• the final r in mar depends on accent:
  • in many Brazilian accents, it is soft, almost like h
  • in others, it is stronger

If you want a more natural Brazilian rhythm, the stress is mainly on:

• TEN in tenho
• DA in saudade
• mar