הרגלית נמצאת מתחת לשלדה.

Because הרגלית is a feminine singular noun, and Hebrew present-tense participles agree with the subject in gender and number.

With נמצא / נמצאת:

• נמצא = masculine singular
• נמצאת = feminine singular
• נמצאים = masculine plural
• נמצאות = feminine plural

So with הרגלית, Hebrew uses נמצאת.

A very common clue is the ending ־ית. Many Hebrew nouns ending in ־ית are feminine.

So even if you do not know the word yet, רגלית looks like a feminine noun, and that matches the feminine verb form נמצאת.

נמצאת is the feminine singular present form of נמצא, from the verb להימצא.

It literally has the sense of be found, but in normal modern Hebrew it is often used to mean be located or be situated.

So in sentences about location, נמצא / נמצאת often works like:

• is located
• is situated
• sometimes simply is

You absolutely can say הרגלית מתחת לשלדה, especially in everyday spoken Hebrew.

The version with נמצאת sounds a bit more:

• explicit
• careful
• formal or written

So the difference is mostly about style, not basic meaning.

Because מתחת normally goes with ל־ before the noun:

• מתחת ל... = under ...
• מעל ל... = above ...
• מתחת לשולחן
• מתחת למיטה

So here the structure is:

מתחת + ל + השלדה

That is why you get מתחת לשלדה, not מתחת השלדה.

Because in Hebrew, the prepositions ב־, כ־, ל־ combine with the definite article ה־.

So:

• ל + השלדה becomes לשלדה

In pronunciation, this definite form is typically la-shilda.

So even though you do not see a separate ה, the noun can still be definite.

Yes — in unpointed Hebrew spelling, לשלדה can represent either:

• lə-shilda = to/for/under a frame depending on context
• la-shilda = to/for/under the frame

So the spelling is the same, and context tells you whether it is definite or indefinite.

That is a very common feature of everyday written Hebrew.

For practical learning purposes, yes: treat מתחת ל־ as a fixed prepositional expression meaning under / underneath / beneath.

So it is best learned as a chunk:

• מתחת ל...
• מתחת לכיסא
• מתחת לשולחן
• מתחת לשלדה

That will sound more natural than trying to analyze it word by word every time.

Yes. Hebrew word order is flexible.

This sentence: הרגלית נמצאת מתחת לשלדה is a neutral, straightforward order.

You could also say:

• מתחת לשלדה נמצאת הרגלית — more marked, more literary, or used for emphasis
• הרגלית מתחת לשלדה — more colloquial, with נמצאת omitted

So the given sentence is a natural standard version, but it is not the only possible order.

A useful pronunciation guide is:

ha-raglít nimtzét mitáchat la-shildá

Approximate stress:

• ragLIT
• nimTZET
• miTAchat
• shilDA

If you are reading slowly, keep in mind that לשלדה here is pronounced with la- if it is definite.

In the present tense, Hebrew often does not use a separate word like English is / are.

For example:

• הספר מעניין = the book is interesting
• הילד בבית = the child is at home

With location, Hebrew can either:

• simply omit is, or
• use נמצא / נמצאת for a more explicit is located

So both patterns are normal:

• הרגלית מתחת לשלדה
• הרגלית נמצאת מתחת לשלדה