Inventamos una historia.

The ending -amos tells you the subject is we (nosotros / nosotras).

So inventamos already includes the idea of we invent or we invented, which is why Spanish often leaves out the subject pronoun.

• Inventamos una historia. = We invent / invented a story.
• Nosotros inventamos una historia. = same meaning, but with extra emphasis on we

Because in Spanish, the verb ending usually makes the subject clear.

With inventamos, a Spanish speaker already knows the subject is we, so nosotros is not necessary.

You would add nosotros only if you want to:

• emphasize who did it
• contrast with someone else
• avoid confusion

For example:

• Nosotros inventamos una historia, no ellos.
  We invented a story, not them.

Because inventar is an -ar verb, and -amos is the we ending for nosotros/nosotras.

In the present tense, regular -ar verbs change like this:

• invento = I invent
• inventas = you invent
• inventa = he/she invents
• inventamos = we invent
• inventáis = you all invent (used in Spain)
• inventan = they/you all invent

So inventamos follows the normal pattern.

Yes. In this form, it can be either:

• present tense: we invent
• preterite: we invented

That happens with many -ar verbs in the we form.

So Inventamos una historia could mean:

• We invent a story (present, depending on context)
• We invented a story (past, depending on context)

Usually, context makes it clear:

• Cada noche inventamos una historia. = present / habitual
• Ayer inventamos una historia. = past

Because historia is a feminine noun, so it uses the feminine article una.

Even though historia begins with h, it is still feminine:

• una historia
• la historia

This is different from some feminine nouns that begin with a stressed a sound, such as:

• el agua
• el águila

But historia does not follow that pattern, so it stays:

• una historia
• la historia

No. In standard Spanish, h is silent.

So historia is pronounced roughly like istoria.

That is why:

• una historia sounds smooth and natural
• the h does not affect pronunciation

It can mean either, depending on context.

• historia = story
• historia = history

In Inventamos una historia, the meaning is clearly story, because you can invent a story.

If someone said:

• Estudio historia.
  that would usually mean I study history.

So the surrounding context tells you which meaning is intended.

This is the most neutral and common Spanish word order:

verb + object

• Inventamos = we invent / invented
• una historia = a story

Spanish word order is fairly flexible, but this version sounds natural and standard.

Other orders are possible, but they may add emphasis:

• Una historia inventamos. → unusual, very marked
• Nosotros inventamos una historia. → emphasizes we

So the original sentence is the straightforward default.

Yes, but it is not exactly the same.

• inventar una historia often suggests making up a story, possibly from imagination
• crear una historia means creating a story, which can sound a bit broader or more deliberate

So:

• Inventamos una historia = we made up a story
• Creamos una historia = we created a story

Both are possible, but inventar is especially natural for something imagined or made up.

In this sentence, yes, una sounds natural because you are talking about a story as a countable thing.

• Inventamos una historia. = natural
• Inventamos historia. = not natural for this meaning

Without the article, the sentence would sound incomplete or would suggest a different meaning.

Yes, but the meaning changes.

• una historia = a story (any story, one story)
• la historia = the story (a specific story already known in context)

So:

• Inventamos una historia. = we invented a story
• Inventamos la historia. = we invented the story

Use la only when the listener already knows which story you mean.

In Spain, it is pronounced approximately:

in-ben-TA-mos

A few useful notes:

• v and b are pronounced very similarly in Spanish
• the stress is on ta: invenTAmos
• the final s is clearly pronounced in standard Peninsular Spanish

So the rhythm is: in-ven-TA-mos

Yes. Inventar is a regular -ar verb.

That means it follows the normal patterns instead of changing unpredictably.

For example, in the present tense:

• invento
• inventas
• inventa
• inventamos
• inventáis
• inventan

This makes it a useful verb for practising regular -ar endings.

Because una historia is the direct object of the verb inventar.

In Spanish, direct objects usually come without a preposition:

• Leo un libro.
• Compramos pan.
• Inventamos una historia.

You only use the personal a with direct objects that are specific people:

• Veo a María.

But una historia is a thing, not a person, so no a is needed.