Kumsala gitmeden önce güneş kremi sürüyorum.

Turkish often uses a verb + suffix + önce/sonra structure for before doing / after doing.

Here:

• gitmek = to go
• gitmeden = without going / before going
• önce = before

So gitmeden önce literally works like before going.

The key part is -meden / -madan, which is added to the verb stem:

• git-meden = before going / without going
• ye-meden = before eating
• çık-madan = before leaving / without leaving

With önce, this very commonly means before doing something.

In this sentence, -meden is the negative adverbial form of the verb, and with önce it gives the meaning before doing.

So:

• gitmek = to go
• gitmeden = without going
• gitmeden önce = before going

On its own, -meden/-madan often means without doing:

• Yemeden çıktım. = I left without eating.

But when followed by önce, it is very naturally understood as before doing:

• Yemeden önce = before eating
• Uyumadan önce = before sleeping

So in your sentence, gitmeden önce means before going.

Because gitmek usually takes the dative case when it means to go to a place.

• kumsal = beach / sandy shore
• kumsala = to the beach

The suffix -a / -e is the dative ending. It often corresponds to English to.

Examples:

• Okula gidiyorum. = I’m going to school.
• Eve gidiyorum. = I’m going home.
• Kumsala gidiyorum. = I’m going to the beach.

So kumsala gitmeden önce literally means before going to the beach.

Turkish often uses the present continuous form for actions that are:

• happening now, or
• habitual / regular in everyday speech

Here:

• sürmek = to apply / spread
• sürüyorum = I am applying / I apply

Even if the English translation is something habitual like I put on sunscreen before going to the beach, Turkish commonly uses -yor for that kind of routine statement.

So güneş kremi sürüyorum can mean:

• I’m applying sunscreen
• I apply sunscreen

depending on context.

A simple present form like sürerim is possible in some contexts, but sürüyorum sounds more natural in many everyday situations.

Yes, sürmek has several meanings, and this is very common in Turkish.

Here it means to apply, to spread, or to rub on.

Common uses:

• krem sürmek = to apply cream
• merhem sürmek = to apply ointment
• ruj sürmek = to put on lipstick

But sürmek can also mean:

• araba sürmek = to drive a car
• uzun sürmek = to last a long time

So the meaning depends on the object and context. With güneş kremi, it clearly means to apply sunscreen.

Because the object here is being used in a general / non-specific way.

In Turkish:

• güneş kremi sürüyorum = I apply sunscreen
• güneş kremini sürüyorum = I am applying the sunscreen

The version without -i on the object is more general, like talking about sunscreen as a substance or category.

The version with the accusative:

• güneş kremini

would usually mean a specific sunscreen, such as one already known in the conversation.

So in a general statement about what you do before going to the beach, güneş kremi sürüyorum is the natural choice.

Because the standard Turkish pattern is:

verb + -madan/-meden + önce

Examples:

• çıkmadan önce = before leaving
• yatmadan önce = before going to bed
• gitmeden önce = before going

So önce follows the verbal form. That is just how this structure is built in Turkish.

It is not usually formed the way English does it, with before first and then a verb in -ing form.

Not completely. Turkish word order is flexible, but some orders sound more neutral than others.

The sentence:

Kumsala gitmeden önce güneş kremi sürüyorum.

is a natural, neutral way to say it.

You could also say:

• Güneş kremi, kumsala gitmeden önce sürüyorum.
• Güneş kremi sürüyorum kumsala gitmeden önce.

But these may sound more marked, more conversational, or more focused on a particular part.

A good rule for learners is:

• keep the time expression first if you want a smooth, neutral sentence
• keep the verb at the end, since that is the most typical Turkish pattern

So the original sentence is a very good standard model.

Yes. Both can refer to the beach, but there is a slight nuance.

• plaj = beach, especially as a place for swimming/sunbathing
• kumsal = sandy shore / beach, often emphasizing the sandy area

So:

• Plaja gitmeden önce güneş kremi sürüyorum.
• Kumsala gitmeden önce güneş kremi sürüyorum.

Both are natural. In many contexts, they are close in meaning. Plaj is often the more general everyday word for a beach destination, while kumsal can sound a bit more like sandy beach / shore.

You know from context.

The form -yor can express:

• an action happening now
• a repeated or habitual action
• a general personal practice

In this sentence, because of kumsala gitmeden önce (before going to the beach), it sounds like a repeated routine:

Before going to the beach, I apply sunscreen.

If someone were describing what they are doing at this very moment, the same form could also mean:

I’m applying sunscreen.

So the grammar form is the same, and context tells you which English translation fits best.

Not naturally in this context. Because of önce, the phrase is understood as before going to the beach.

Compare:

• Kumsala gitmeden önce güneş kremi sürüyorum. = Before going to the beach, I apply sunscreen.
• Kumsala gitmeden güneş kremi sürüyorum. = I apply sunscreen without going to the beach.
  This would sound odd in most situations, but grammatically it shows the without doing meaning more clearly.

So once önce is added, the intended meaning is before going.