यह लिफ़ाफ़ा नया है।

A word-by-word breakdown is:

• यह = this
• लिफ़ाफ़ा = envelope
• नया = new
• है = is

So the sentence structure is literally This envelope new is, which is the normal kind of word order in Hindi.

Hindi usually puts the verb at the end of the sentence. That includes the verb to be.

So:

• English: This envelope is new
• Hindi: यह लिफ़ाफ़ा नया है।
  • literally: This envelope new is

This is one of the most basic word-order differences between English and Hindi.

In this sentence, नया is not directly describing the noun inside a noun phrase; it is part of the statement being made about the noun.

Compare:

• यह नया लिफ़ाफ़ा है। = This is a new envelope.
  • Here नया comes before लिफ़ाफ़ा because it is directly modifying the noun.
• यह लिफ़ाफ़ा नया है। = This envelope is new.
  • Here नया is a predicate adjective, so it comes before है, not before the noun.

So both are correct, but they mean slightly different things.

Because लिफ़ाफ़ा is a masculine singular noun, and नया is an adjective that agrees with it.

For many common Hindi adjectives, the ending changes like this:

• masculine singular: नया
• feminine singular: नई
• masculine plural: नए
• feminine plural: नई (same form as feminine singular in many contexts)

So:

• यह लिफ़ाफ़ा नया है। = This envelope is new.
• यह किताब नई है। = This book is new.

You usually learn the gender of Hindi nouns along with the noun itself. In this case, लिफ़ाफ़ा is masculine.

A helpful clue is that many masculine nouns end in -ा, though this is not a perfect rule.

Because लिफ़ाफ़ा is masculine singular, the adjective and verb pattern match that:

• लिफ़ाफ़ा → masculine singular
• नया → masculine singular form
• है → singular is

Not always. यह can function as both:

• a demonstrative: this
• a pronoun: this / he / she / it depending on context

In a sentence like यह लिफ़ाफ़ा नया है, it clearly means this because it is followed by a noun.

Examples:

• यह अच्छा है। = This is good. / He is good. / It is good.
  The exact meaning depends on context.
• यह लड़का अच्छा है। = This boy is good.

Hindi does not have articles like English a, an, and the.

So लिफ़ाफ़ा can mean:

• an envelope
• the envelope
• just envelope

The context tells you which one is meant.

In यह लिफ़ाफ़ा नया है, the word यह already makes it specific, so the meaning is naturally this envelope.

In careful spelling-based pronunciation, यह may be explained as yah, but in normal modern speech it is very often pronounced more like yeh.

So learners commonly hear:

• यह → yeh

This is completely normal. Many textbooks even write yeh in transliteration.

The dot under फ़ is called a nukta. It changes the sound of फ.

• फ = traditionally an aspirated p sound
• फ़ = f sound

So लिफ़ाफ़ा is pronounced roughly lifaafaa, not liphaaphaa.

In modern Hindi, some speakers do not strongly distinguish these sounds, but the spelling with फ़ shows the borrowed f sound.

No, it is a loanword, ultimately from Persian/Urdu usage. Hindi contains many such borrowed everyday words.

That is very normal in Hindi. Learners do not need to worry about the origin too much; the important thing is to learn how the word behaves in Hindi:

• it is masculine
• singular direct form: लिफ़ाफ़ा
• plural direct form: लिफ़ाफ़े

You would change the demonstrative, the noun ending, the adjective ending, and the verb:

• singular: यह लिफ़ाफ़ा नया है।
• plural: ये लिफ़ाफ़े नए हैं।

Breakdown of the plural:

• यह → ये = these
• लिफ़ाफ़ा → लिफ़ाफ़े = envelopes
• नया → नए = new
• है → हैं = are

So ये लिफ़ाफ़े नए हैं। means These envelopes are new.

Both are forms of the verb to be in the present tense.

• है = is for singular subjects
• हैं = are for plural subjects, and also for respectful singular in many cases

So:

• यह लिफ़ाफ़ा नया है। = This envelope is new.
• ये लिफ़ाफ़े नए हैं। = These envelopes are new.

In very colloquial speech, many speakers pronounce यह as ये, even when the meaning is singular this.

So you may hear:

• ये लिफ़ाफ़ा नया है।

But in standard written Hindi, यह is the usual singular form, while ये is usually plural these or a spoken variant. For learning and writing, it is best to keep:

• यह = this
• ये = these

The main change would be the adjective form.

For example, with किताब (book), which is feminine:

• यह किताब नई है। = This book is new.

Compare:

• masculine: यह लिफ़ाफ़ा नया है।
• feminine: यह किताब नई है।

So the adjective changes to match the gender of the noun.