Learn Hardcore Russian: Наш учитель очень добрый и часто улыбается. - Our teacher is very kind and often smiles.

So Наш учитель очень добрый literally looks like “Our teacher very kind”, but it is understood and translated as “Our teacher is very kind.”

What gender is учитель, and why is it добрый, not добрая?

The noun учитель (teacher) is masculine in Russian.

Adjectives must agree in gender, number, and case with the noun they describe. Since учитель is masculine singular, you also use the masculine singular form of the adjective:

наш учитель – our (male) teacher
очень добрый – very kind (masculine form)

That’s why the sentence has:

Наш учитель очень добрый…

and not:

Наша учитель очень добрая… (this is ungrammatical, because наша / добрая are feminine forms, but учитель is masculine)

If you want to make it clearly about a female teacher, Russian often uses a different noun:

учительница – feminine form of teacher
- Наша учительница очень добрая и часто улыбается.

Why is it наш учитель, not наша / наше / наши учитель?

The possessive pronoun наш (our) must agree with the noun it refers to:

наш – masculine singular
наша – feminine singular
наше – neuter singular
наши – plural

Since учитель is masculine singular, you must use наш:

наш учитель – our (male) teacher
наша учительница – our (female) teacher
наше дело – our business (neuter)
наши учителя – our teachers (plural)

So наш учитель is the only correct choice here.

What case is учитель in, and why does it look like the dictionary form?

In Наш учитель очень добрый и часто улыбается, the word учитель is the subject of the sentence. Subjects in Russian are normally in the nominative case.

The dictionary form of a noun is also the nominative singular. So:

Dictionary form: учитель
In the sentence: учитель (same form, nominative singular)

This is why you don’t see any extra ending or change on учитель here.

Why can one и (“and”) connect очень добрый and часто улыбается when one is an adjective and the other is a verb?

In the sentence:

Наш учитель очень добрый и часто улыбается.

both parts describe the same subject (наш учитель):

(Он) очень добрый – He is very kind.
(Он) часто улыбается – He often smiles.

Russian allows you to connect two different types of predicates (an adjective predicate and a verb predicate) with и as long as they belong to the same subject. The subject он / наш учитель is just understood for the second part and not repeated.

So the meaning is:

Наш учитель (есть) очень добрый и (он) часто улыбается.
→ Our teacher is very kind and (he) often smiles.

Why is the verb улыбается reflexive (with -ся)?

The verb улыбаться means “to smile”, and it is always reflexive in Russian. Many Russian verbs related to feelings, states, or actions that “happen to you” or on your face/body are reflexive:

улыбаться – to smile
смеяться – to laugh
бояться – to be afraid
гордиться – to be proud

The -ся / -сь ending is the reflexive marker:

улыбать – (theoretically: “to make someone smile”; not used by itself)
улыбаться – “to smile” (reflexive)

In our sentence:

(он) улыбается – he smiles / he is smiling

How is улыбается formed, and what person/tense is it?

The infinitive is улыбаться – to smile (imperfective aspect).

It is a 1st conjugation verb in the present tense. Its forms (singular) are:

я улыбаюсь – I smile
ты улыбаешься – you smile (informal)
он / она / оно улыбается – he / she / it smiles

So улыбается is:

3rd person singular, present tense, imperfective
Subject: он / наш учитель

This matches the subject наш учитель (he), so:

Наш учитель … улыбается. – Our teacher … smiles.

Why is it часто улыбается, and can часто go somewhere else?

Часто means “often” and is an adverb. The most neutral position for adverbs of frequency in Russian is before the verb:

Он часто улыбается. – He often smiles.

Other positions are possible, but they can sound more marked or emphasize something different:

Он улыбается часто.
– Grammatically correct, but sounds more like you’re stressing the fact that this smiling is frequent, maybe in contrast to some other behavior.
Часто он улыбается.
– Also correct, but sounds stylistically marked; the часто at the beginning is used for emphasis (“Often, he smiles.”).

In the original sentence, очень добрый и часто улыбается is the most natural, neutral word order.

Why do we say очень добрый and not something like очень улыбается?

Очень means “very” and usually modifies adjectives or adverbs, not verbs directly.

очень добрый – very kind (очень
- adjective)
очень красивый – very beautiful
очень быстро – very quickly (очень
- adverb)

It cannot modify a finite verb like улыбается in the same way:

очень улыбается – sounds wrong in Russian

To intensify the verb улыбается, Russian would use other words or structures, for example:

Он всегда улыбается. – He always smiles.
Он много улыбается. – He smiles a lot.
Он часто и широко улыбается. – He often smiles broadly.

So очень naturally goes with добрый, not with улыбается.

How do you pronounce the words учитель, добрый, часто, улыбается? Where is the stress?

The stress and approximate pronunciation are:

учитель – учитель
- Stress on -чи-: [u-CHEE-tyelʹ]
добрый – добрый
- Stress on до-: [DOH-bryy] (the ый is short, like “ɨ”)
часто – часто
- Stress on ча-: [CHAS-ta], with ч like ch in chair
улыбается – улыба́ется
- Stress on -ба-: [oo-ly-BA-ye-tsa]

Unstressed о is usually pronounced like a short а in normal speech, so добрый sounds closer to [DAH-bryy] in fast, relaxed pronunciation.