das Fläschchen
small bottle
A small bottle for liquids of various kinds.
Im Labor füllte sie die Probe in ein kleines Fläschchen.
In the lab, she filled the sample into a small bottle.

small bottle
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small bottle
A small bottle for liquids of various kinds.
Im Labor füllte sie die Probe in ein kleines Fläschchen.
In the lab, she filled the sample into a small bottle.

'Fläschchen' (small bottle) is the diminutive form of 'die Flasche' (the bottle). The ending '-chen' makes the noun small and always changes the article to 'das'. The vowel 'a' becomes 'ä' (umlaut).
Für die Reise habe ich mein Shampoo in ein kleines Fläschchen gefüllt.
For the trip, I filled my shampoo into a small bottle.
Nouns that end in '-chen' have the same form in the plural as in the singular. You recognize the plural only from the article or the context.
Ein Fläschchen steht auf dem Tisch.
One small bottle is on the table.
When a 'Fläschchen' (bottle) is mentioned in connection with a 'Baby' (baby), 'Kind' (child), 'Milch' (milk), or 'Nahrung' (food/formula), it always means the feeding bottle for infants.
Der Vater bereitet das Fläschchen für die Nacht vor.
The father is preparing the bottle for the night.
In the context of baby food, the phrase 'das Fläschchen geben' (to give the bottle) is often used. It means to feed the baby with a bottle.
Kannst du dem Baby bitte das Fläschchen geben? Es hat Hunger.
Can you please give the baby its bottle? It's hungry.
You can recognize the meaning 'small bottle with alcohol' from the context. Drinks such as 'Schnaps' (schnapps) or 'Likör' (liqueur) are often mentioned, or the situation (e.g., a hike) suggests it.
Zur Stärkung trank er einen Schluck aus seinem Fläschchen mit Kräuterlikör.
To strengthen himself, he took a sip from his small bottle of herbal liqueur.
bottle
'die Flasche' and 'das Fläschchen' both refer to a container for liquids. The main difference is size, and often also the context. A 'Flasche' can be small or large and is the normal, general word. A 'Fläschchen' is a small bottle; the word often sounds more delicate or refers to something small, for example medicine, perfume, or a baby bottle. Learners may confuse the words because 'Fläschchen' comes from 'Flasche'. If the size is not important, 'Flasche' usually fits. If the small form is being emphasized, 'Fläschchen' is more precise.

Am Morgen steht ein kleines Fläschchen mit Hustensaft auf dem Tisch.
In the morning, there is a small bottle of cough syrup on the table.
Vor dem Kurs legt das Kind eine Flasche Wasser in den Rucksack.
Before class, the child puts a bottle of water in the backpack.