El espíritu de equipo permaneció fuerte.

In Spanish, it is very common to use the definite article with nouns when speaking in a general or specific way. So El espíritu de equipo sounds natural and complete.

Leaving out El here would sound unnatural in normal Spanish. English often drops the article in expressions like team spirit, but Spanish usually keeps it: el espíritu de equipo.

Espíritu de equipo is the standard Spanish expression for team spirit. It refers to the sense of unity, cooperation, and shared motivation within a group.

Literally, it is something like spirit of team, but you should understand it as the fixed expression team spirit.

De equipo is used because this is a general expression: team spirit.

• espíritu de equipo = team spirit, the quality itself
• espíritu del equipo = the spirit of the team, meaning the spirit belonging to a particular team

So in this sentence, de equipo is the more idiomatic choice if you are talking about the general idea of team spirit.

Permaneció is the preterite of permanecer, in the third person singular: he/she/it remained.

Here it matches el espíritu de equipo, which is singular, so the verb is singular too.

• yo permanecí
• tú permaneciste
• él/ella permaneció

The preterite permaneció presents the staying strong as a completed fact or as part of a finished event or period.

For example, it suggests something like:

• during the match, despite the problems, the team spirit remained strong

If you said permanecía fuerte, that would sound more descriptive or ongoing, with less emphasis on a completed whole.

Very roughly:

• permaneció fuerte = it remained strong
• permanecía fuerte = it was remaining strong / it used to remain strong / it remained strong in an ongoing descriptive sense

Because fuerte here is an adjective, not an adverb. It describes the noun espíritu.

The structure is:

• el espíritu = the subject
• permaneció = the verb
• fuerte = an adjective describing how the spirit was

In English, after verbs like remain, stay, become, and seem, we also use adjectives:

• It remained strong not
• It remained strongly

Spanish works the same way here.

Fuerte is an adjective that does not change for masculine/feminine in the singular.

So you get:

• el espíritu fuerte
• la voluntad fuerte

It only changes for number:

• el espíritu fuerte
• los espíritus fuertes

Yes. Siguió siendo fuerte is a very natural alternative and often sounds a bit more explicit in English terms because it literally means continued to be strong.

Compare:

• permaneció fuerte = remained strong
• siguió siendo fuerte = continued being strong / continued to be strong

Both are correct. Permaneció fuerte is a little more concise and formal in tone.

Yes, permanecer is a normal verb, but it often sounds a bit more formal or literary than some alternatives.

For example:

• permaneció fuerte = slightly more formal/written
• siguió fuerte or siguió siendo fuerte = often more everyday

So the sentence sounds natural, but somewhat polished or written rather than very casual conversation.

The normal word order is verb + complement:

• El espíritu de equipo permaneció fuerte.

Putting fuerte earlier would usually sound marked, poetic, or emphatic. The standard neutral order is the one in your sentence.

The infinitive is permanecer.

It is mostly regular, but like many -cer verbs, it has a spelling change in some forms to preserve pronunciation:

• permanezco = I remain

That zc appears before o. But in permaneció, there is no special spelling issue beyond the normal accent mark of the preterite form.

The written accent shows the stress: es-PÍ-ri-tu.

Without the accent mark, Spanish stress rules would suggest a different pronunciation, so the accent is necessary.

Also, espíritu is an example of a word with esdrújula stress, meaning the stress falls on the third-to-last syllable. All such words take a written accent in Spanish.

A broad Spain pronunciation would be approximately:

el es-PÍ-ri-tu de e-KI-po per-ma-ne-THIÓ FWER-te

Notes:

• espíritu stresses PÍ
• equipo stresses KI
• permaneció stresses the final Ó
• In much of Spain, c before i is pronounced like th in think, so permaneció sounds like permanethió

Yes, if the context requires it:

• Los espíritus de equipo permanecieron fuertes is grammatically possible

But in practice, espíritu de equipo is often treated as an abstract quality, so the singular is much more common unless you are comparing different groups or teams.

Yes, it is natural and correct. It sounds slightly formal or like something from a report, article, commentary, or narration.

In more everyday speech, people might also say:

• El espíritu de equipo siguió fuerte
• El espíritu de equipo se mantuvo fuerte

But your sentence is perfectly good Spanish.