اگر هوا بهتر بود، من و خواهرم با دوچرخه تا دریا میرفتیم.

In Persian, اگر ... بود is a very common way to make an unreal / hypothetical condition, much like English if ... were or if ... was in everyday speech.

So in:

اگر هوا بهتر بود

the verb بود is literally the past form of to be, but here it is being used to express a situation that is not true now or is only imagined:

• اگر هوا بهتر بود = If the weather were better

This is similar to English, where we often use a past-looking form in hypothetical statements:

• If I had more time...
• If the weather were better...

So yes, it looks past, but its function here is hypothetical, not simply past.

Great question. The form می‌رفتیم can mean different things depending on context:

• we were going
• we used to go
• we would go

In this sentence, because it follows a hypothetical اگر clause, it means:

• we would go

So:

• اگر هوا بهتر بود، ... می‌رفتیم
• If the weather were better, ... we would go

This is a very normal Persian pattern:

• اگر ... بود، ... می‌رفتیم
• If ... were, ... would go

So the grammar is built from a past/imperfective-looking form, but the meaning is modal/hypothetical.

The prefix میـ usually marks the imperfective aspect in past-tense forms. That often gives meanings like:

• ongoing past: was/were doing
• habitual past: used to do
• in some conditional sentences: would do

Here, because the sentence is hypothetical, می‌رفتیم is best understood as would go.

Breakdown:

• رفت = went
• می‌رفت = was going / used to go / would go
• می‌رفتیم = we were going / we used to go / we would go

So the exact English translation depends on context, and here the context clearly points to would go.

Yes. بهتر means better, and it is the comparative form of خوب (good).

So:

• خوب = good
• بهتر = better
• بهترین = best

In this sentence:

• هوا بهتر بود = the weather was/were better

Persian comparatives are often used without any extra word corresponding to English more:

• بزرگ = big
• بزرگ‌تر = bigger
• خوب = good
• بهتر = better

Note that بهتر is irregular, just like English good → better.

Persian does not have a word exactly like English the.

So nouns often appear without an article, and the listener understands from context whether the meaning is:

• a
• the
• or just a general noun

Examples:

• هوا = weather / the weather
• دریا = sea / the sea

In your sentence:

• اگر هوا بهتر بود naturally means If the weather were better
• تا دریا naturally means to the sea

So Persian relies much more on context than English does for article-like meanings.

Both are possible.

• من و خواهرم
• خواهرم و من

Both mean my sister and I / I and my sister.

Persian is fairly flexible here. The order may depend on:

• what sounds natural to the speaker
• what they want to emphasize
• personal style

In everyday Persian, من و ... is very common and natural.

Also, unlike formal English, Persian does not have a strict school-rule preference equivalent to always putting yourself second.

خواهرم means my sister.

It is made of:

• خواهر = sister
• ـم = my

So:

• خواهرم = my sister
• برادرم = my brother
• دوستم = my friend
• کتابم = my book

This ـم is a possessive ending attached directly to the noun.

Other common possessive endings are:

• ـم = my
• ـت = your
• ـش = his/her
• ـمان = our
• ـتان = your (plural / formal)
• ـشان = their

Yes, با usually means with, but it is also used to express means of transportation in many contexts.

So:

• با دوچرخه = by bicycle / on a bicycle
• literally: with a bicycle

This is a normal Persian way to say how someone travels.

Other examples:

• با ماشین = by car
• با اتوبوس = by bus
• با قطار = by train

So even though با literally means with, in these travel expressions it often corresponds to English by.

تا basically means up to / as far as / until.

In this sentence, تا دریا means something like:

• as far as the sea
• to the sea
• all the way to the sea

It emphasizes the extent or endpoint of the trip.

By contrast, به is the more basic preposition for to:

• به دریا = to the sea

So the difference is roughly:

• به دریا = destination
• تا دریا = up to/as far as that destination

In many real-life contexts, both could work, but تا دریا can feel a bit more like talking about the distance or route.

Because this sentence has no direct object.

The main verb is رفتن (to go), which is an intransitive verb here. The sentence contains:

• a subject: من و خواهرم
• a manner phrase: با دوچرخه
• a destination/end point: تا دریا

But there is no noun receiving the action as a direct object.

The marker را is used for definite direct objects, for example:

• کتاب را خواندم = I read the book

Since دریا here is part of a prepositional/directional phrase, not a direct object, there is no را.

It is perfectly natural Persian and can be used in everyday speech.

A few notes:

• In careful writing, you would usually write می‌رفتیم with a half-space.
• Many learners see it written as میرفتیم when typing informally, but می‌رفتیم is the standard spelling.

The sentence itself is neutral and natural:

• not overly formal
• not slangy
• not bookish

So yes, it is a good everyday model sentence.

A natural pronunciation would be close to:

agar havâ behtar bud, man-o khâharam bâ docharkhe tâ daryâ mi-raftim

A few helpful notes:

• اگر = agar
• هوا = havâ
• بهتر = behtar
• بود = bud
• خواهرم = khâharam
• دوچرخه = docharkhe
• دریا = daryâ
• می‌رفتیم = mi-raftim

In connected speech, من و خواهرم may sound a bit like:

• mano khâharam

That is very normal in spoken Persian.

Yes. Persian has several ways to express conditionals, depending on style and nuance.

Your sentence uses a very common pattern:

• اگر ... بود، ... می‌رفتیم

This is excellent standard Persian for a hypothetical situation.

In other contexts, speakers might phrase things differently, but this structure is one of the main patterns learners should know for if ... were ..., would ... meanings.

So for learning purposes, this sentence is a very useful model:

• اگر + past form
• then imperfective past in the result clause

That combination often gives an unreal present meaning:

• If X were true, Y would happen.