Sie spannt das Tuch über den Tisch.

Here it means she.

Why?

• spannt is 3rd person singular
• she
  • spannt fits
• they would be sie spannen
• formal you (Sie) would also be Sie spannen

So even though Sie is capitalized, that is just because it is at the beginning of the sentence. The verb form tells you it must be she.

The infinitive is spannen.

In this sentence, spannt is:

• 3rd person singular
• present tense
• from the regular verb spannen

Common meanings of spannen include:

• to stretch
• to tighten
• to pull taut

In this sentence, stretch / spread taut is the best fit.

Because Tuch is a neuter noun.

Its basic article is:

• das Tuch = the cloth

It is also the direct object of the sentence, but for a neuter noun, the article stays das in both nominative and accusative singular.

So:

• nominative: das Tuch
• accusative: das Tuch

Because den Tisch is in the accusative.

The preposition über can take different cases, and here it takes the accusative. Also, Tisch is masculine:

• nominative: der Tisch
• accusative: den Tisch

So the noun itself stays Tisch, but the article changes from der to den.

Über is a two-way preposition (Wechselpräposition), which means it can take either:

• accusative for direction / movement / extension
• dative for location

Here, the cloth is being stretched over/across the table, so German uses the accusative:

• über den Tisch

Compare:

• Sie spannt das Tuch über den Tisch. = she stretches the cloth over/across the table
• Das Tuch hängt über dem Tisch. = the cloth hangs above the table

So über den Tisch suggests movement or placement across the table, not just location above it.

This is a very common question.

• über den Tisch = over/across the table, with direction or extension
• über dem Tisch = above the table, in a fixed location

In this sentence, the cloth is being stretched so that it goes over the table’s surface. That is why German uses über den Tisch.

If you said über dem Tisch, it would sound more like the cloth is somewhere above the table in the air.

Not with exactly the same meaning.

• auf den Tisch means onto the table
• über den Tisch means over/across the table

So:

• Sie legt das Tuch auf den Tisch. = she puts the cloth onto the table
• Sie spannt das Tuch über den Tisch. = she stretches the cloth over/across the table

Über gives the idea of covering or extending across the table, not just placing something on it.

Not necessarily.

Tuch is a general word meaning:

• cloth
• piece of fabric
• sometimes rag or cloth covering, depending on context

A specific tablecloth is usually die Tischdecke.

So this sentence says the cloth, not specifically the tablecloth. Of course, in context, the cloth could be functioning like a table covering.

The sentence follows normal German main-clause word order:

• Sie = subject
• spannt = verb
• das Tuch = direct object
• über den Tisch = prepositional phrase

So the pattern is:

Subject + verb + object + prepositional phrase

That is a very standard German structure.

Yes. German allows quite a bit of flexibility, as long as the finite verb stays in second position in a main clause.

For example:

• Sie spannt das Tuch über den Tisch.
• Über den Tisch spannt sie das Tuch.

Both are grammatical, but the emphasis changes.

The original sentence is the most neutral and straightforward version.

Because most masculine nouns in German do not change their noun ending in the accusative singular. Usually only the article changes:

• der Tisch
• den Tisch

So the case marking is mainly visible on der/den, not on Tisch.

Some nouns do change in other patterns, but Tisch is a normal noun and does not.

Yes. spannt is present tense, and German present tense is often used where English uses either:

• she stretches
• she is stretching

So depending on context, this sentence could describe:

• a habitual action
• an action happening right now

German does not need a separate progressive form like English is stretching.

Roughly like shpant.

A few useful pronunciation points:

• word-initial sp in native German words is usually pronounced shp
• so spannt starts with shp-
• the a is short here
• the final t is clearly pronounced

So not English-style spant, but closer to shpant.

Tuch is pronounced roughly like tooch, but with the German ch sound at the end.

Important points:

• Tu- sounds like too
• the final ch is not like English ch in chair
• after u, German ch is the back-of-the-mouth sound heard in words like Buch

So Tuch is approximately too-kh, with a soft fricative at the end.

Yes. Spannen is a regular (weak) verb.

Its present-tense forms are:

• ich spanne
• du spannst
• er/sie/es spannt
• wir spannen
• ihr spannt
• sie/Sie spannen

So spannt is exactly the expected form for she.