Im April regnet es manchmal, aber der Garten wird wieder grün.

German main clauses follow the verb-second rule: the finite verb must be in the second position.

So in:

Im April regnet es manchmal

the first position is taken by the time expression Im April, and the verb regnet comes second.

That means the subject-like es comes after the verb.

Compare:

• Es regnet im April manchmal.
• Im April regnet es manchmal.

Both are possible, but the second one sounds more natural if you want to emphasize the time.

Im is a contraction of in dem.

• in dem April → im April

With months, German often uses in + dative article to mean in a certain month.

So:

• im April = in April

Even though English usually has no article here, German commonly does in this structure.

It is in the dative case.

That is because the preposition in takes the dative here when it refers to time rather than movement.

• im April = in dem April
• dem is dative

So the phrase is a dative time expression.

Yes, but this is a special kind of it.

In German weather verbs often use an impersonal es, just like English does in it is raining.

• Es regnet. = It is raining.

This es does not refer to a real thing. It is just there because German, like English, normally wants a subject-like element in the sentence.

Because Im April is in first position, and German main clauses keep the verb in second position.

So the order becomes:

1. Im April
2. regnet
3. es
4. manchmal

If the sentence started with es, then you would get:

• Es regnet manchmal im April.

That is also grammatical, but it has a slightly different emphasis.

Manchmal means sometimes.

It is an adverb of frequency. In this sentence it comes after the subject-like es:

• Im April regnet es manchmal

That placement is very normal.

German adverbs can sometimes move, but the meaning or emphasis may change a little. For example:

• Im April regnet es manchmal.
• Im April manchmal regnet es. — much less natural here

So for learners, regnet es manchmal is the safest pattern.

Because aber is a coordinating conjunction.

Coordinating conjunctions connect two main clauses and do not send the verb to the end.

So:

• ..., aber der Garten wird wieder grün.

The second clause keeps normal main-clause word order, with the verb in second position:

1. der Garten
2. wird
3. wieder
4. grün

This is different from subordinating conjunctions like weil or dass, which push the verb to the end.

Compare:

• ..., aber der Garten wird wieder grün.
• ..., weil der Garten wieder grün wird.

Garten is a masculine noun, so its basic dictionary form is:

• der Garten = the garden

Here it is the subject of the second clause, so it stays in the nominative case:

• der Garten wird wieder grün

If it were in another case, the article would change, for example:

• den Garten = accusative
• dem Garten = dative

But here it is the thing that is becoming green, so nominative der Garten is correct.

Because werden + adjective often expresses a change of state.

• Der Garten ist grün. = The garden is green.
  This describes a state.
• Der Garten wird grün. = The garden becomes / gets green.
  This describes a change.

So in your sentence, the idea is that after winter or bad weather, the garden becomes green again.

Because grün is a predicate adjective after werden.

In German, verbs like sein, werden, and bleiben are often followed by an adjective that describes the subject:

• Der Garten ist grün.
• Der Garten wird grün.
• Der Garten bleibt grün.

That adjective usually comes later in the clause, and here it naturally appears at the end:

• der Garten wird wieder grün

Because it is a predicate adjective, not an adjective directly before a noun.

Compare:

• der grüne Garten → adjective before a noun, so it takes an ending
• der Garten ist grün → predicate adjective, so no ending
• der Garten wird grün → also predicate adjective, so no ending

So grün stays in its basic form here.

Here wieder means again.

So:

• wird wieder grün = becomes green again

It suggests that the garden was green before, then it was not green for a while, and now it returns to that state.

In some contexts wieder can also feel like back, as in green again/back to green.

Because wieder modifies the idea of becoming green, and this placement is the natural one in German:

• der Garten wird wieder grün

You can think of it as attaching closely to the new state grün.

German adverb placement can be flexible, but this order is the standard and most idiomatic one here.

Because in German, all nouns are capitalized.

So:

• April is a noun
• Garten is a noun

Also, Im is capitalized because it is the first word of the sentence.

This is one of the most noticeable spelling differences between German and English.

Yes, that is grammatical, but it changes the meaning slightly.

• wird wieder grün = the garden is becoming green again
• ist wieder grün = the garden is green again

So wird focuses on the process or change, while ist focuses on the resulting state.

Yes. It is in the present tense.

German often uses the present tense for:

• general truths
• habitual actions
• seasonal patterns
• things happening now

So:

• Im April regnet es manchmal = In April, it sometimes rains
• der Garten wird wieder grün = the garden becomes green again

This is completely normal German usage.