En esta avenida nueva hay un carril bici, así que mi hermana prefiere venir al trabajo en bicicleta.

Both are possible, but they can sound slightly different.

In Spanish, adjectives usually come after the noun: avenida nueva = new avenue/street.

So en esta avenida nueva is the most neutral, straightforward order.

If you say en esta nueva avenida, putting nueva before the noun can sound a little more descriptive or stylistic, as if you are highlighting the fact that the avenue is new. In everyday speech, both are understandable.

Esta means this and agrees with avenida, which is a feminine singular noun.

So:

• este = this (masculine singular)
• esta = this (feminine singular)
• estos = these (masculine plural)
• estas = these (feminine plural)

Because avenida is feminine, Spanish uses esta.

Hay is the Spanish form used to say there is or there are.

It comes from the verb haber, but in this use it does not change for singular or plural:

• Hay un carril bici = There is a bike lane
• Hay dos carriles bici = There are two bike lanes

So unlike English, Spanish uses the same word, hay, for both singular and plural existence.

Carril bici means bike lane or cycle lane.

Literally:

• carril = lane
• bici = bike, short for bicicleta

In Spain, carril bici is a very common expression. You may also hear:

• carril para bicicletas = lane for bicycles
• vía ciclista = cycling route/infrastructure

But carril bici is the usual everyday phrase.

The article un goes with carril, not with bici.

The main noun is carril, and carril is masculine:

• un carril

Bici here functions like a modifier, almost like bike in bike lane in English. So the gender of bicicleta does not control the article in this phrase.

Así que means so, therefore, or as a result.

It links the first idea to the consequence:

• There is a bike lane on this new avenue,
• so my sister prefers to come to work by bicycle.

It is a very common way to introduce a result in spoken and written Spanish.

Similar connectors include:

• por eso = that’s why / for that reason
• entonces = then / so
• de modo que = so / therefore

In modern Spanish, possessives like mi, tu, su, nuestro usually go before the noun and do not take an article.

So:

• mi hermana = my sister
• tu casa = your house

Using an article before that kind of possessive is not standard in normal modern Spanish. You would not say la mi hermana in standard contemporary usage.

There are two separate points here.

First, after preferir, Spanish normally uses an infinitive:

• prefiere venir = she prefers to come

You cannot say prefiere va because va is a conjugated form, not an infinitive. It would need to be:

• prefiere ir = she prefers to go
• prefiere venir = she prefers to come

Second, venirse is possible in some contexts, but it usually adds a nuance such as come over, come along, or a more colloquial/pronominal feel. Here, plain venir is the normal choice.

This is a very common question.

Spanish chooses between venir (to come) and ir (to go) based on the speaker’s point of reference.

If the speaker is speaking from the workplace, or mentally treating the workplace as the destination relevant to the conversation, venir al trabajo can make sense: to come to work.

In English, come to work is also possible in some contexts, though go to work is often more common.

So venir is not automatically wrong here. It depends on perspective. If the speaker were talking from home or from a neutral point of view, ir al trabajo might also be natural.

Al is the contraction of a + el:

• a el → al

So:

• venir al trabajo = to come to work

This contraction is required whenever a is followed by the masculine singular article el, except with some proper names or fixed expressions.

Compare:

• voy al mercado = I’m going to the market
• llego al hotel = I arrive at the hotel

But:

• voy a la oficina = I’m going to the office

There is no contraction with la.

Because trabajo here means work in the sense of the workplace/job context, and Spanish usually uses the article in this kind of expression:

• ir al trabajo
• venir al trabajo

English often says simply to work, without an article, but Spanish often needs one where English does not.

So:

• en bicicleta = by bicycle
• al trabajo = to work

This is one of those places where Spanish and English structure things differently.

To say by bicycle, Spanish normally uses en bicicleta.

This is the standard expression for means of transport in this case:

• en bicicleta = by bike
• en coche = by car
• en tren = by train

You may also hear ir en bici, where bici is the short everyday form.

Por bicicleta is not natural here, and con bicicleta would mean something more like with a bicycle, not specifically by bicycle as a mode of transport.

Yes, basically.

• bicicleta = the full word, more formal/neutral
• bici = very common short form, everyday speech

In this sentence, Spanish uses both:

• carril bici = bike lane
• en bicicleta = by bicycle

That is completely natural. You could also say en bici in conversation:

• Mi hermana prefiere venir al trabajo en bici

That version sounds a little more informal and very common in Spain.

Because mi hermana is the subject of the verb prefiere, not the direct object.

The personal a is used before a specific human direct object, for example:

• Veo a mi hermana = I see my sister

But here:

• mi hermana prefiere...

Your sister is doing the action, so she is the subject, and no personal a is used.

The original sentence is already natural. In more casual speech in Spain, someone might say:

En esta avenida nueva hay carril bici, así que mi hermana prefiere venir al trabajo en bici.

Possible casual differences:

• dropping un before carril bici in some contexts
• using en bici instead of en bicicleta

But the original version is perfectly correct and clear.