suki?

I always thought suki was used to describe your like in a non-romantic way.

For example

Takeshisan ga suki desu
I like Takeshi (he's cool to go surfing with)

daisuki was the term I thought you used for romantic purposes

Josesan ha Marikosan ga daisuki da to omou.
I think Jose really likes (in a romantic way) Mariko.

In my (amateur) experience, you'd say someone is fun or interesting (omoshiroi) rather than you directly like them (suki).

For romance, suki (and daisuki) is the way to go.

'Suki' is a versatile term. You can put 'na' on the end to say something is your favorite, but used in context here, it is definitely what you would say to a girlfriend or boyfriend. If you said suki in reference to any other person, it would come off as a little...weird.

Moving from 'suki' to 'daisuki' is the equivalent of moving from 'like' to 'love' in English. So in a serious, long-term relationship, you would use 'daisuki'.

The use of 'aishiteru' really comes down to personal preference, but you would definitely never, ever say it to anyone that you weren't already engaged to (or otherwise planning to marry). Even then, some people tend to avoid it. You hear it mostly in movies and anime where the characters' romance is based on the idea of the red string of fate or something similar. I'm to understand that most couples only use it comfortably after going through some sort of crisis together, even when they're married.

For instance, a married couple tries for five years to have a baby. The wife gets pregnant, and loses the baby at 7 months. For a while afterward, their marriage is very rocky. The wife confronts her husband about fearing that their marriage will end, and he tells her not to worry and says 'aishiteru'. And even though he's said it that time, that doesn't mean they'll completely transition to 'aishiteru'. They'll still probably use 'daisuki' for the most part.

Unless you make it clear otherwise, it sounds like you have a crush on Takeshi-san.

I am sure where you heard that "na" business. To say something is your favorite I would use "Ichiban suki". "Na" is used when describing something. "Suki na hito" is "a person I like".

I used to think the same thing, but I'm willing to trust my own experience (and MMM's, whose Japanese is years ahead of mine, from what I can tell).

My mom has a Japanese penpal, and when my mom sent her a picture
that she took on the beach (my dad had written "i love holly" -her name-
in seaweed), her Japanese penpal thought it was the sweetest thing,
because they didn't really say "i love you" in Japan as much.

But I also heard that it's becoming more common with the new generation.

I read "daisuki da yo" somewhere too. So I guess that's another way to say it.

And the reason it's pronounced "ski" is because the U in some Japanese words isn't pronounced. Like in "desu"

Suki is a -na adjective. So, to put it in place of a verb when talking about something would mean that it is liked, and usually to mean that it's your favorite.

From your website:

Uh, what?

Suki is a na adjective. "to like" is a verb in English. So when you talk about "vegetables you like" it is "suki na yasai". A car you like is "suki na kuruma". The "na" there has nothing to do with "favorite".

"Suki" CAN mean favorite, but it depends in the context.