huraipan ni abura wo sukosi irete, ninniku to syouga wo saki ni itamemasu.

Because the verb 入れる uses に to mark the place something goes into.

• フライパンに油を入れる = put oil into the frying pan

Here, フライパン is the destination/container, so に fits naturally.

A learner might expect で, but で usually marks the place where an action happens. In this sentence:

• フライパンに goes with 入れて
• the frying pan is also understood as the place where 炒めます happens, but that location is not separately marked again

を marks the direct object of the verb.

So in 油を入れて, the thing being put in is 油. That makes 油 the object of 入れる.

The same thing happens later:

• にんにくとしょうがを炒めます
• garlic and ginger are the things being stir-fried, so they take を

少し means a little or a small amount.

In this sentence, it most naturally means add a little oil. So it works like an adverb modifying 入れて, but in English we would often express it as modifying the noun:

• 油を少し入れて = add a little oil

Japanese often allows this kind of flexible placement. It is not written as 少しの油 here, but the meaning is still clearly a small amount of oil.

The て-form connects actions in sequence.

So:

• 油を少し入れて、にんにくとしょうがを先に炒めます。

means something like:

• add a little oil, and then
• stir-fry the garlic and ginger first

The て-form is very common in instructions and recipes because it links steps smoothly.

It can mean any of those depending on context.

With oil and a frying pan, natural English would usually be:

• add oil
• pour a little oil into the pan

Japanese 入れる is broader than any single English verb here. It simply means to put something into something else, and context tells you the most natural English wording.

Japanese often omits the subject when it is obvious from context.

In a recipe or instruction, the hidden subject is basically:

• you should do this or
• one does this

So the sentence does not need to say あなたは. In fact, adding it would usually sound unnecessary in this kind of context.

と connects the two nouns:

• にんにくとしょうが = garlic and ginger

That whole combined noun phrase becomes the object of 炒めます, so only one を is needed at the end:

• にんにくとしょうがを炒めます

This is exactly like saying garlic and ginger as one combined object in English.

先に means first, before that, or ahead of the other ingredients/steps.

So 先に炒めます means:

• stir-fry them first

In a recipe, this implies that something else will be added later. It tells you the garlic and ginger should go in before the later ingredients.

They are similar, but the nuance is a little different.

• 最初に = at the very beginning
• 先に = first / before the others / ahead of the next step

In recipes, 先に often sounds very natural because it highlights order relative to what comes next:

• にんにくとしょうがを先に炒めます
• stir-fry the garlic and ginger first, before adding the other things

If you used 最初に, the meaning would still be understandable, but 先に feels especially natural when comparing one step with later steps.

炒める means to stir-fry / sauté / fry in a pan with oil.

That fits garlic and ginger in a frying pan very well.

By contrast, 焼く is broader and often means grill, bake, or cook by direct heat. It can also mean fry in some contexts, but for this recipe-style action, 炒める is the more precise and natural choice.

Right. Normal Japanese is usually written without spaces:

• フライパンに油を少し入れて、にんにくとしょうがを先に炒めます。

Spaces are often added in teaching materials for beginners to make the parts easier to see. They are not part of standard Japanese writing.

Because they are different kinds of words.

• フライパン is katakana because it is a loanword, from frying pan
• にんにく and しょうが are often written in hiragana in recipes, even though they can also be written with kanji:
  • にんにく = 大蒜
  • しょうが = 生姜

Recipes often prefer hiragana for readability, especially for food items and common function words.

Yes. The final verb 炒めます is in the polite ます-form.

Recipes and instructions often use either:

• polite style: 炒めます
• plain style: 炒める
• command-like instructional style: 炒めてください, 炒める, or even shorter recipe style

Using ます makes it sound polite and standard, which is common in teaching materials and many recipe explanations.