Wij wieden weliswaar vaak, maar wij oogsten veel.

Weliswaar is a somewhat formal Dutch word that signals a concession: you admit one point before giving a contrasting point. In English, it often corresponds to things like admittedly, it is true that, or although it is true that.

So in this sentence, weliswaar tells you: yes, the first clause is true, but that is not the whole story.

They often work together as a set:

weliswaar ..., maar ...

This is a very common Dutch pattern for contrast. A natural English equivalent is:

admittedly ..., but ...

So:

Wij wieden weliswaar vaak, maar wij oogsten veel.

has the structure:

It is true that we weed often, but we harvest a lot.

Without maar, the contrast would feel unfinished.

Both wij and we mean we.

The difference is mainly this:

• we = the normal unstressed form, very common in everyday speech
• wij = the full, stressed form, often a bit more formal or emphatic

So the sentence is correct with wij, but in everyday speech many people would more naturally say:

We wieden weliswaar vaak, maar we oogsten veel.

Because maar joins two separate main clauses:

• Wij wieden weliswaar vaak
• maar wij oogsten veel

Repeating the subject is completely normal and makes the sentence sound balanced and clear.

If the subject stays the same, Dutch can also leave it out in the second clause:

Wij wieden weliswaar vaak, maar oogsten veel.

That is also grammatical. Repeating wij just sounds a bit fuller, and sometimes a bit more emphatic.

Because both parts are main clauses, and Dutch main clauses normally follow the V2 rule: the finite verb comes in second position.

In the first clause:

• Wij = first element
• wieden = finite verb in second position

In the second clause:

• wij = first element
• oogsten = finite verb in second position

So the word order is exactly what you expect in a Dutch main clause.

Yes, but the structure changes.

Hoewel means although and introduces a subordinate clause, not a main clause. So you would say:

Hoewel wij vaak wieden, oogsten wij veel.

That is also correct Dutch.

So the difference is:

• weliswaar ..., maar ... = two linked main clauses
• hoewel ... = a subordinate clause plus a main clause

They are similar in meaning, but not identical in grammar or style.

Yes, both are regular verbs.

In the present tense, wij/we usually takes the same form as the infinitive:

• wij wieden
• wij oogsten

A few singular forms are:

• ik wied
• ik oogst
• hij/zij wiedt
• hij/zij oogst

So in your sentence, wieden and oogsten are simply the normal present-tense forms used with wij.

Veel means a lot / much / many, depending on context.

In this sentence, it expresses quantity: we harvest a lot. Dutch often leaves the exact thing being harvested unstated if it is clear from the context.

So:

• wij oogsten veel = we harvest a lot
• wij oogsten veel groenten = we harvest a lot of vegetables

In other words, veel can stand on its own without a noun after it.

Yes, vaak is in a natural position here.

In a normal Dutch main clause, adverbs like vaak often come after the finite verb:

• Wij wieden vaak
• Wij wieden weliswaar vaak

This sounds natural.

You can move things around for style or emphasis, but not every position sounds equally good. For example:

• Weliswaar wieden wij vaak, maar wij oogsten veel.
  This is possible, but more formal/literary.

By contrast, Wij wieden vaak weliswaar sounds awkward, because weliswaar usually wants to introduce the concessive contrast earlier.

It sounds a bit formal or written, mainly because of weliswaar and the repeated wij.

The sentence is perfectly correct, but in everyday spoken Dutch many speakers would use something simpler, such as:

We wieden vaak, maar we oogsten veel.

or, if they want to keep the concessive idea:

We wieden wel vaak, maar we oogsten veel.

So the original sentence is good Dutch, just slightly more polished or formal in tone.