Este jersey me aprieta un poco, así que prefiero la camisa blanca.

Because jersey is a masculine noun in Spanish, so it takes the masculine demonstrative este.

• este = this (masculine)
• esta = this (feminine)

So:

• este jersey
• esta camisa

Even though jersey ends in -y, its gender is still masculine.

In Spain, jersey is the normal word for a sweater / jumper. It is very common in Peninsular Spanish.

A learner may notice that other Spanish-speaking countries often prefer words like:

• suéter
• pulóver
• chompa (in some countries)

So jersey is especially useful to know for Spanish from Spain.

In me aprieta, the pronoun me means to me / on me, but in natural English we usually translate the whole idea as it’s tight on me or it squeezes me.

The verb apretar literally means to squeeze, to press, or to tighten.

So:

• Este jersey me aprieta = This sweater feels tight on me / This sweater is squeezing me

Spanish often uses this structure:

• [thing] + me/te/le... + verb

Examples:

• Estos zapatos me aprietan. = These shoes are tight on me.
• La chaqueta me queda grande. = The jacket is too big on me.

So me is there because the sweater is affecting me.

Because the subject is este jersey, which is singular.

• Este jersey me aprieta. = This sweater is tight on me.
• Estos jerseys me aprietan. = These sweaters are tight on me.

The verb agrees with the thing doing the action, not with me.

Un poco means a little or a bit.

Here it softens the statement:

• me aprieta un poco = it’s a little tight

Its position is very natural after the verb phrase:

• me aprieta un poco

You can often place un poco after the verb or after the part it modifies:

• Estoy un poco cansado.
• Me gusta un poco menos.

In this sentence, me aprieta un poco is the most natural wording.

Así que means so, therefore, or so that’s why. It introduces a result.

• Este jersey me aprieta un poco, así que prefiero la camisa blanca. = This sweater is a little tight, so I prefer the white shirt.

By contrast, porque means because and introduces a reason.

Compare:

• Prefiero la camisa blanca porque este jersey me aprieta un poco. = I prefer the white shirt because this sweater is a little tight.

So:

• porque = because
• así que = so

Spanish often leaves out subject pronouns when they are not needed, because the verb ending already shows who the subject is.

• prefiero = I prefer

The ending -o tells you it is I.

So both are possible:

• Prefiero la camisa blanca.
• Yo prefiero la camisa blanca.

But the version without yo is more neutral and more common.
You would use yo mainly for emphasis or contrast:

• Yo prefiero la camisa blanca, pero ella prefiere la azul.

Yes. Preferir is a stem-changing verb.

In many present-tense forms, the e changes to ie:

• yo prefiero
• tú prefieres
• él/ella prefiere
• nosotros preferimos
• vosotros preferís
• ellos prefieren

So in this sentence, prefiero is irregular in the present tense.

In Spanish, descriptive adjectives usually come after the noun.

So:

• la camisa blanca = the white shirt

That is the normal order.

Putting the adjective before the noun is possible in some cases, but it often sounds more literary, emotional, or stylistically marked. For everyday speech, la camisa blanca is the natural choice.

Also notice agreement:

• camisa is feminine singular
• so the adjective is blanca, not blanco

Spanish often uses the definite article more naturally than English does.

Here, la camisa blanca refers to a specific item: the white shirt. The speaker is probably choosing between clothes, so the article sounds completely natural.

If you said prefiero camisa blanca, that would sound incomplete or unnatural in this context.

So:

• prefiero la camisa blanca = I prefer the white shirt

Yes, but it changes the structure slightly.

Two natural options are:

• Este jersey me aprieta un poco.

  • literally: This sweater squeezes me a little
  • very natural when clothes feel tight on your body

• Este jersey está un poco apretado.

  • literally: This sweater is a little tight
  • also natural, but describes the garment more directly

Both can work, but me aprieta focuses more on how it feels on the person.

Yes, it sounds very natural in Spain.

A few specifically natural features for Spain are:

• jersey for sweater/jumper
• me aprieta for clothing that feels tight
• así que for so
• omission of yo in prefiero

So this is a good, idiomatic sentence for everyday Peninsular Spanish.