यह प्लान असफल रहा।

यह means this here, referring to this plan.

In modern speech, it is often pronounced roughly like yeh. In very careful reading, you may also hear something closer to yah, but yeh is what learners will commonly hear in everyday Hindi.

प्लान is a borrowed word from English plan, written in Devanagari. This is very common in modern Hindi, especially in casual speech, business, media, and everyday conversation.

A more traditionally Hindi/Sanskrit-based alternative would be योजना.

So these are both possible:

• यह प्लान असफल रहा।
• यह योजना असफल रही।

The second one sounds more formal or more purely Hindi.

असफल is an adjective meaning unsuccessful or failed.

It is built from:

• सफल = successful
• अ- = a negative prefix, like un- in English

So:

• सफल = successful
• असफल = unsuccessful

In this sentence, असफल is describing प्लान.

Both can be possible, but they are not exactly the same in feel.

• असफल था = was unsuccessful
• असफल रहा = remained unsuccessful / turned out to be unsuccessful / ended up unsuccessful

In many contexts, असफल रहा is a very natural way to say that something failed. It often sounds a bit more event-focused or result-focused than था.

So:

• यह प्लान असफल था। = This plan was unsuccessful.
• यह प्लान असफल रहा। = This plan failed / remained unsuccessful.

In real usage, असफल रहा is very common in news, reports, and formal narration.

Here रहा comes from the verb रहना, which often means to remain or to stay.

So literally, असफल रहा is something like:

• remained unsuccessful

But in natural English, that is often best translated simply as:

• failed
• was unsuccessful

So रहा is not just a random helper word here; it adds the idea of a resulting state or continued state.

Because रहा agrees with प्लान, which is treated as masculine singular.

Agreement pattern:

• masculine singular: रहा
• feminine singular: रही
• plural masculine: रहे
• plural feminine: रहीं (though in speech, forms can simplify)

Examples:

• यह प्लान असफल रहा। = This plan failed.
• यह योजना असफल रही। = This plan/scheme failed. (योजना is feminine)
• ये प्लान असफल रहे। = These plans failed.

Because this sentence is not using a transitive perfective structure like राम ने काम किया.

Here, प्लान is not an agent doing a direct action to something else. Instead, the sentence is describing the state/result of the plan:

• The plan was unsuccessful
• The plan failed

So no ने is needed.

This is normal with predicates like:

• वह बीमार रहा। = He remained ill.
• प्रयास सफल रहा। = The effort was successful.
• योजना असफल रही। = The scheme failed.

The basic order is very natural Hindi word order:

• यह = this
• प्लान = plan
• असफल = unsuccessful
• रहा = remained/was

So the structure is basically:

this plan unsuccessful remained

Hindi usually places the main descriptive part before the verb, so this order is expected.

You could move things around for emphasis in some contexts, but यह प्लान असफल रहा। is the standard, neutral order.

Yes, यह can sometimes function like this or it, depending on context.

But in this sentence, the most natural meaning is this:

• यह प्लान = this plan

If the plan had already been mentioned, English might translate it as the plan or even it, but the Hindi form still remains यह if the speaker is referring to something near in context or focus.

You would say:

यह योजना असफल रही।

Why does it change? Because योजना is a feminine noun, so रहा changes to रही.

Comparison:

• यह प्लान असफल रहा।
• यह योजना असफल रही।

The meaning is basically the same, but योजना sounds more formal or more standard Hindi.

Yes, several ways are possible. For example:

• यह प्लान असफल रहा।
  Very natural; somewhat formal-neutral.

• यह योजना विफल रही।
  More formal; विफल is another word for failed/unsuccessful.

• यह प्लान फेल हो गया।
  Very colloquial, using English fail adapted into Hindi speech.

• यह योजना कामयाब नहीं हुई।
  Literally This plan did not succeed.

All of these can work, but असफल रहा is a solid standard expression.

If you want to negate the idea, you usually place नहीं before the verb phrase:

• यह प्लान असफल नहीं रहा। = This plan was not unsuccessful.

But notice: in English, not unsuccessful is awkward and often implies partial success. So in real Hindi, people usually prefer a more direct positive sentence, such as:

• यह प्लान सफल रहा। = This plan was successful.
• यह प्लान कामयाब रहा। = This plan was successful.

So while असफल नहीं रहा is grammatically possible, it is not always the most natural choice.