Parecía imposible al principio.

Parecía is the imperfect tense of parecer.

The imperfect is used because the sentence describes how something seemed at that time, as a background impression or ongoing state in the past. It is not presenting that impression as a single completed event.

So parecía imposible means something like:

• it seemed impossible
• it looked impossible
• it was apparently impossible

If you said pareció imposible, that would sound more like a specific moment when it seemed impossible.

A rough contrast:

• Parecía imposible al principio. = It seemed impossible at first.
• Pareció imposible en ese momento. = It seemed impossible at that moment.

The base verb is parecer.

Parecer commonly means:

• to seem
• to appear
• sometimes to look like

In this sentence, it means to seem.

Some useful examples:

• Parece fácil. = It seems easy.
• Me parece bien. = It seems fine to me / I think that’s fine.
• Parecía imposible. = It seemed impossible.

Spanish often omits subject pronouns when they are clear from the verb form or from context.

So Parecía imposible al principio naturally means:

• It seemed impossible at first

English needs it, but Spanish usually does not.

The sentence could refer to:

• a situation
• a task
• a plan
• something already mentioned in context

In natural Spanish, saying ello parecía imposible would usually sound unnecessarily formal or unnatural in everyday speech.

It follows a very common Spanish pattern:

parecer + adjective

Here:

• parecía = seemed
• imposible = impossible

So the structure is simply:

• It seemed + adjective

Other examples of the same pattern:

• Parecía difícil. = It seemed difficult.
• Parecía raro. = It seemed strange.
• Parecía perfecto. = It seemed perfect.

You do not need an article before the adjective. Spanish just says parecía imposible, not something like parecía un imposible.

Imposible is an adjective, and in this sentence it agrees with the implied thing or situation being described.

A useful point: imposible has the same form for masculine and feminine singular.

So you get:

• un plan imposible
• una tarea imposible

In this sentence, the subject is not stated explicitly, so imposible stays in its singular form because it refers to one thing or one overall situation.

If the subject were plural, it would become imposibles:

• Parecían imposibles al principio. = They seemed impossible at first.

Al principio means:

• at first
• at the beginning
• initially

It is a very common expression in Spanish.

Examples:

• Al principio, no entendía nada. = At first, I didn’t understand anything.
• Al principio parecía fácil. = At first it seemed easy.
• Parecía imposible al principio. = It seemed impossible at first.

Because a + el contracts to al in Spanish.

So:

• a + el = al

That is why you say:

• al principio

not

• a el principio

This contraction is mandatory in normal Spanish, except when el is part of a proper name.

For example:

• Voy al mercado. = I’m going to the market.
• Llegamos al final. = We arrived at the end.

Usually, no, not if you mean at first.

These expressions mean different things:

• al principio = at first / at the beginning
• en principio = in principle
• en el principio = in the beginning, but usually in a very literal, formal, or biblical sense

So for this sentence, al principio is the natural choice.

Compare:

• Parecía imposible al principio. = It seemed impossible at first.
• En principio, es una buena idea. = In principle, it’s a good idea.

It can refer to different kinds of subjects, depending on context.

Because the subject is omitted, parecía could refer to:

• it seemed impossible
• he seemed impossible
• she seemed impossible

However, in most normal contexts, parecía imposible is understood as referring to a situation, task, plan, or problem.

If you were talking about a person, the exact meaning would depend heavily on context. For example, it could mean someone seemed impossible to deal with, but that is less neutral and more context-dependent.

Because the sentence is giving a general statement about how something seemed, without saying to whom it seemed impossible.

If you want to say who had that impression, you can add an indirect object pronoun:

• Me parecía imposible. = It seemed impossible to me.
• Le parecía imposible. = It seemed impossible to him/her.
• Nos parecía imposible. = It seemed impossible to us.

Without that pronoun, the sentence just states the appearance or impression more neutrally:

• Parecía imposible al principio.

The written accent in parecía shows where the stress falls:

• pa-re-CÍ-a

The accent is important because it marks the stressed í and helps show the verb ending clearly.

This -ía ending is very common in the imperfect tense for -er and -ir verbs:

• comía
• vivía
• parecía

So the accent is not optional; it is part of the correct spelling.

Yes. Spanish word order is fairly flexible here.

These both work:

• Parecía imposible al principio.
• Al principio parecía imposible.

The second version may sound slightly more natural if you want to emphasize at first.

Both mean the same thing.

Very often, yes, that is the natural implication.

Al principio suggests an early stage, so listeners often expect a contrast, such as:

• Parecía imposible al principio, pero al final lo conseguimos. = It seemed impossible at first, but in the end we managed it.

However, the sentence by itself does not absolutely require that later it became possible. It mainly tells you about the initial impression.