Sentence translation...

[Wladimir]

I need help about one sentence. I tried to say: "Love is like war, easy to start, hard to finish, impossible to forget"

My Japanese isn't so good, I used my Oxford minidictionary and I got this:

愛はような戦争です。簡単始まる。難しい終える。無理 忘れる。

Is this grammatical correct or not... Please help! Thanks for reading...

[Glenn]

愛というのはすなわち、戦争のようです。始めるのは簡単。終えるのは難しい。忘れるのは不可能 。

There's an attempt, but you'll want to wait for a native speaker to clear that up. A couple of things, though:

1) Something other than a particle has to come before よう; for example, ここに置いたような気がする (I get the feeling I left it here), ドアのノブのような物 (something like a door knob), 山のような高波 (a (tall) wave like a mountain).

2) 簡単 is either an adjective (形容動詞 or な形容詞, to be more specific) or an adverb. In either case it's followed by either な (when it's an adjective) or に (when it's an adverb), so 簡単始まる isn't a very good sentence, but 簡単に始まる is fine.

3) Similarly, 難しい is also an adjective (形容詞 in this case, slightly different), so it can't just modify a verb. You have to make it into an adverb, which would be 難しく.

[undrentide]

I need help about one sentence. I tried to say: "Love is like war, easy to start, hard to finish, impossible to forget"

My Japanese isn't so good, I used my Oxford minidictionary and I got this:

愛はような戦争です。簡単始まる。難しい終える。無理忘れる。

Is this grammatical correct or not... Please help! Thanks for reading...

I'm afraid that such a sentence is rather complicated for a beginner... You need to learn the basics, how particles work, and certain expressions.
Perhaps you need grammar books as well as dictionaries.
:relief:

"Love is like war,
愛はような戦争です。
Your sentence sounds something like "love war like is".

like ~ : ～のよう、～に似ている. (The latter means is resemble to ~ if I translate more precisely.)

You can say
愛は戦争のようです。
but
愛は戦争に似ている
would sounds more natural in this context.

easy to start, hard to finish, impossible to forget"
簡単始まる。難しい終える。無理忘れる。
These are not sentences but just putting words together...

adjective + to + verb can be translated like
easy to ~ : ～やすい
hard to ~ : ～にくい、～がたい
impossible to ~　: ～できない、～られない
but to understand them you need to know conjugation of adjective and verb, also they are not the best choice for this particular translation.
So let's see easier one.

（ｖｅｒｂ）のは（ａｄｊｅｃｔｉｉｖｅ） : to do ~ is [adjective]
Note: の can be replaced by こと. Both nominalize verbs.

easy to start
始めるのは簡単だ。
or
始めるのはやさしい。

hard to finish,
終えるのは難しい。

impossible to forget
忘れるのは不可能だ。

Now let's put them together.
When connecting i-adjective to another phrase, conjugation is ～く instead of ～い
In case of na-adjective, you should change だ to で.

愛は戦争に似ている。始めるのは簡単で、終えるのは難しく、わすれることは不可能だ。

---
edit: haha, Glenn san beat me!

[Elizabeth]

hard to finish,
終えるのは難しい。
Or "Owaraseru no ha muzukashii." Difficult to make end. :-)

[Elizabeth]

"Love is like war,
[SIZE=2]愛はような戦争です。
[SIZE=1]Your sentence sounds something like "love war like is".

like ~ : ～のよう、～に似ている. (The latter means is resemble to ~ if I translate more precisely.)

You can say
愛は戦争のようです。
but
愛は戦争に似ている
would sounds more natural in this context.
I've always gotten similar corrections in the direction of you to nite, but why I wonder ?? What makes it more natural here and not in other contexts ? :?

[Wladimir]

Thank you so so much both of you, Glenn and undrentide!!!
You really helped me a lot.

I will try to buy some grammer books soon, because I hard find this small dictionary here in Serbia. I downloaded some articles about grammer from Wikipedia, but they're nothing special.

[undrentide]

I've always gotten similar corrections in the direction of you to nite, but why I wonder ?? What makes it more natural here and not in other contexts ? :?

It really is a difficult question for me!
...Perhaps it is more of a question of style?