Learn Hardcore Finnish: Lähetän sinulle linkin siihen videoon, jos haluat kerrata asian. - I will send you a link to that video if you want to review the matter.

Lähetän is present tense, 1st person singular of lähettää (“to send”).
Finnish uses the present tense for both present and future meanings.
The time reference (“now” vs. “in the future”) is understood from context or extra words like huomenna (tomorrow), kohta (soon), etc.

So Lähetän sinulle linkin… can mean:

“I am sending you the link…” (right now), or
“I’ll send you the link…” (later, as in your sentence).

The context with jos haluat kerrata asian makes it sound like a future intention.

Why is it sinulle and not sinua or sinun?

These are different cases of the pronoun sinä (“you”, singular):

sinä = you (subject form)
sinun = your (genitive, possession)
- sinun kirjasi = your book
sinua = you (partitive object or after certain verbs)
- Rakastan sinua. = I love you.
sinulle = to you, for you (allative case)

In this sentence, sinulle marks the recipient of the sending:

Lähetän sinulle linkin…
= I will send a link to you.

So the -lle (allative) ending is used because something is being given/sent to someone.

Why is it linkin and not linkki?

Linkin is the object of the verb lähetän, and it appears in the genitive-accusative (-n) form:

Basic form: linkki = a link
Genitive/total object: linkin = the link (as a whole thing that gets sent)

Finnish often uses the genitive (-n) to mark a total object when the action is seen as complete or affecting the whole object:

Lähetän linkin. = I will send the (whole) link.
Syön omenan. = I will eat the (whole) apple.

Using just linkki here (Lähetän linkki) would be ungrammatical. The object needs marking, and in this context the correct form is linkin.

What exactly does siihen videoon mean, and why not just videoon?

Siihen videoon literally means “into that video / to that video”, and it’s built from:

se = that
- illative form: siihen = into that / to that
video = video
- illative form: videoon = into the video / to the video

Together:

linkin siihen videoon ≈ “a link to that video”.

Why the demonstrative siihen?

It points to a specific, known video, usually one both speaker and listener already know from context (“that video we just talked about”).
Without siihen, just linkin videoon would sound incomplete or odd; Finnish likes to use a demonstrative here when you mean a particular known thing.

So siihen videoon is like English “to that video”, with both words carrying the case ending (illative).

What is the difference between siinä, siitä, and siihen?

These are all case forms of se (“that”):

siinä – in/on that (inessive)
- Pidän siitä kirjasta, joka on siinä pöydällä.
siitä – from that / about that (elative)
- Puhumme siitä videosta. = We are talking about that video.
siihen – into that / to that (illative)
- Lähetän linkin siihen videoon. = I’ll send a link to that video.

In your sentence, linkki johonkin (“a link to something”) typically takes the illative, so we use siihen (“to that”) + videoon.

Why is videoon used with the -oon ending instead of just videon?

Videoon is in the illative case, which often expresses movement/direction “into / to” something.

Basic form: video
Genitive/total object: videon (of the video / the video as object)
Illative (into/to): videoon

The pattern is: video + -on → videoon (the vowel is lengthened, so you see a double o).

The structure with linkki is:

linkki johonkin = link to something
→ linkin siihen videoon = a link to that video

If you said linkin siitä videosta, that would more naturally mean “a link from/about that video”, not “a link to that video”. The illative videoon is the natural choice for “to the video”.

Can you drop the comma before jos:
Lähetän sinulle linkin siihen videoon jos haluat kerrata asian?

In standard written Finnish, no – the comma is required.

Rule of thumb:

A subordinate clause starting with jos (“if”) is separated from the main clause by a comma.

So you write:

Lähetän sinulle linkin siihen videoon, jos haluat kerrata asian.
Jos haluat kerrata asian, lähetän sinulle linkin siihen videoon.

Unlike English, you don’t normally omit this comma in formal or neutral written Finnish.

Why is it haluat and not haluaisit? What’s the nuance?

Both forms exist, but they differ in mood and politeness:

haluat = you want (present indicative)
- neutral, direct statement of wanting
haluaisit = you would like (conditional)
- softer, more polite, more tentative

In your sentence:

jos haluat kerrata asian
= “if you want to review the topic”.
jos haluaisit kerrata asian
= “if you would like to review the topic” (more polite, more hypothetical, more “up to you”).

The given sentence (jos haluat) is friendly and neutral, not especially formal or especially soft.

Why is kerrata in the infinitive form and not conjugated, like kerratat?

Finnish uses a conjugated verb + infinitive pattern, similar to English “want to do”:

haluat kerrata = (you) want to review
haluan syödä = I want to eat
aion katsoa = I am going to watch

Only the first verb (haluat) is conjugated for person and number.
The second verb (kerrata) stays in the basic infinitive (1st infinitive) form.

Also, kerratat is not a correct Finnish form.
The conjugation of kerrata in the present is:

minä kertaan
sinä kertaat
hän kertaa
me kertaamme
te kertaatte
he kertaavat

So if you really wanted to conjugate it after removing haluat, you’d say e.g. Kertaat asian = “You review the topic.”

What exactly does kerrata mean here – “revise”, “review”, or “repeat”?

Kerrata means “to go over something again”, usually in the sense of studying or reviewing material you already know.

Typical uses:

kerrata sanastoa = revise/review vocabulary
kerrata kielioppia = go over grammar again
kerrata koealuetta = review the exam material

In school/learning contexts, kerrata is very close to:

British English: “revise”
General English: “review / go over again”

It is not primarily about “repeating words out loud” (that would be more like toistaa, lausua uudelleen, etc.), but about mentally and/or actively going through the content again to reinforce it.

Why is it asian and not asiaa?

Both asian and asiaa come from asia (“thing”, “matter”, “topic”), but they mark the object in different ways:

asian = genitive-accusative (total object)
- suggests the topic is handled as a whole, with a completed action
asiaa = partitive object
- can suggest partial / ongoing / indefinite action, or an uncountable mass

In your sentence:

jos haluat kerrata asian
≈ “if you want to review the (whole) topic / that matter we talked about.”

This fits well because it refers to a specific, bounded thing you can review from start to finish.

If you said jos haluat kerrata asiaa, it would sound more like:

“if you want to do some reviewing of the topic (in general / to some extent)”,
with more focus on the activity of reviewing than on a specific, complete unit of content.

So asian (total object) is the natural choice here.

Can we change the word order to Jos haluat kerrata asian, lähetän sinulle linkin siihen videoon? Does that change the meaning?

Yes, that word order is perfectly correct, and the basic meaning stays the same.

Lähetän sinulle linkin siihen videoon, jos haluat kerrata asian.
- Slight emphasis on “I’ll send you the link”; the condition (“if you want to review it”) comes as an added note.
Jos haluat kerrata asian, lähetän sinulle linkin siihen videoon.
- Slight emphasis on the condition first: “If you want to review it, (then) I’ll send you the link.”

This is mostly about information structure and emphasis, not about grammatical correctness. Both versions are natural.

Where is the word for “I”? Why isn’t it Minä lähetän?

In Finnish, the person ending on the verb already tells you who the subject is.

lähetän ends in -n, which marks 1st person singular = “I send”.
Therefore minä is optional unless you want to emphasize I in contrast to someone else.

Compare:

Lähetän sinulle linkin. = I’ll send you a link. (neutral)
Minä lähetän sinulle linkin.
= I will send you the link (not someone else / emphasizing “me”).

So the sentence is complete and natural without minä.