La camiseta técnica es ligera.

Because camiseta is a feminine noun in Spanish, so it takes the feminine singular article la.

A useful rule is that many nouns ending in -a are feminine, and camiseta follows that pattern:

• la camiseta
• una camiseta

That feminine gender also affects the adjectives in the sentence, which is why you see técnica and ligera in the feminine form too.

They end in -a because they must agree with camiseta, which is feminine singular.

In Spanish, adjectives usually agree with the noun in:

• gender: masculine or feminine
• number: singular or plural

So:

• la camiseta técnica es ligera = feminine singular
• el pantalón técnico es ligero = masculine singular
• las camisetas técnicas son ligeras = feminine plural

This kind of agreement is one of the biggest differences from English.

In Spanish, adjectives often come after the noun, especially when they are simply describing a type or quality.

So camiseta técnica is the normal order for technical sports shirt / performance shirt.

English often puts adjectives before the noun:

• technical shirt

Spanish often puts them after:

• camiseta técnica

That said, some adjectives can come before the noun in Spanish, but doing so can change the tone, emphasis, or meaning.

Because es comes from ser, which is used for characteristics seen as more inherent, defining, or general.

Here, ligera describes a general quality of the shirt, so ser is the natural choice:

• La camiseta técnica es ligera.

If you used estar, it would sound unusual here, because estar is more often used for states, conditions, or location.

Very roughly:

• ser = what something is
• estar = how something is or where it is

So for a basic description like this, es is correct.

The accent mark shows which syllable is stressed.

técnica is pronounced with the stress on the téc- syllable:

• TÉC-ni-ca

Without the accent mark, Spanish pronunciation rules would normally place the stress differently, so the written accent is necessary.

It also helps you identify the related forms:

• técnico = masculine singular
• técnica = feminine singular
• técnicos = masculine plural
• técnicas = feminine plural

It is a very common combination, especially in sports, outdoor clothing, and activewear contexts.

Camiseta técnica usually refers to a shirt made for exercise or performance, often with special fabric that is breathable, quick-drying, or designed for sport.

So although it is grammatically just noun + adjective, in real usage it often works like a familiar product label.

Normally, no. In Spanish, when the noun is the subject of a sentence like this, you usually need the article:

• La camiseta técnica es ligera.

Leaving it out sounds unnatural in a normal sentence.

You might omit the article only in special contexts, such as:

• labels
• headlines
• notes
• product listings

For example, in a catalogue heading, Camiseta técnica ligera could be fine. But as a full sentence, La camiseta técnica es ligera is the standard form.

Because Spanish often does not need an explicit subject pronoun when the subject is already clear.

In this sentence, the subject is not it anyway; it is the full noun phrase:

• La camiseta técnica

So instead of saying something like It is light, Spanish naturally says:

• La camiseta técnica es ligera.

Spanish does allow pronouns like ella, but using them here would usually sound unnecessary unless you were contrasting or emphasizing something.

In standard usage, that sounds wrong or at least very unnatural.

Ligera here describes a general property of the shirt, so Spanish uses ser:

• La camiseta técnica es ligera.

A good way to think about it is:

• weight, material qualities, and general characteristics usually go with ser
• temporary states usually go with estar

So a shirt is light, but it is not normally said to be in a light state.

The plural is:

Las camisetas técnicas son ligeras.

Each part changes to match the plural:

• la → las
• camiseta → camisetas
• técnica → técnicas
• es → son
• ligera → ligeras

This is a good example of how much agreement Spanish uses compared with English.

Grammatically, Spanish sometimes allows adjectives before the noun, but la técnica camiseta would not sound natural here.

The normal and idiomatic expression is:

• la camiseta técnica

Putting técnica before the noun would sound odd because this adjective is classifying the noun as a type of shirt, not adding poetic or emotional emphasis.

So for everyday Spanish, stick with:

• camiseta técnica

A simple pronunciation guide is:

la kah-mee-SEH-tah TEHK-nee-kah es lee-HEH-rah

A few helpful points for Spain Spanish:

• c before e in camiseta is pronounced like the th in thin in much of Spain
• g before e in ligera has a throaty sound, like a strong h
• the stress falls on:
  • camiSEta
  • TÉCnica
  • liGEra

If you speak Latin American Spanish, the c in camiseta is usually an s sound instead.

In Spain, ligera is the more natural choice here.

Liviana exists, but it is much more common in many parts of Latin America than in Spain. For Spain Spanish, ligera is the safer and more natural word for lightweight in this context.

So if you are specifically learning Spanish from Spain, ligera is the better option.