My father was slightly/a little like a pack rat.

[Anna232]

Can I use "slightly" in the first sentence to mean a little bit?
1.My father was *slightly* /a little like a pack rat.
2.But all the things that he bought were organized. Should I use "all the things" instead of "all things?"
3. I am very careful about/with throwing things. Is either "about" or "with" correct in this sentence?
4.As my experience shows it is better to make sure that something is garbage/trash/rubbish. Can either word be used?
5.There were a lot of situations where I felt sorry after throwing things away. Should I use "about" instead of "after?"

 

[emsr2d2]

1. space here My father was slightly/a little like a pack rat.
Can I use "slightly" in the first sentence to mean a little bit? No.

Of those two, only "a little like" works there. You could also say "My father was a bit of a pack rat". In BrE, we'd call him a "hoarder".

2. space here But All the things that he bought were organized.
Should I use "all the things" instead of "all things?"

As a learner, don't try to start sentences with "but". What do you mean by saying that his things "were organised"?
You need the definite article there.

3. I am very careful about/with throwing things.
Is either "about" or "with" correct in this sentence?

I don't understand the sentence. What "things" are you referring to and why are you throwing them? *Based on sentence 5, I think you mean "throwing things away". If that's the case, use "about" or "when".

4. space here As my experience shows In my experience, it is better to make sure that something is garbage/trash/rubbish [before discarding it].
Can either all three words be used?

Note my corrections above. In this context, all three words are OK. BrE wouldn't use "trash" and I don't think AmE uses "rubbish".

5. space here There were a lot of situations where I felt sorry after regretted throwing things something away.
Should I use "about" instead of "after?"

Neither. Note my correction above.

You need to work on consistency. With sentence 1, you asked a question and then wrote the sentence. In the other four, you wrote the sentence and then asked a question. You put a space after "3." but failed to put the space after all the other numbers followed by a full stop. Take the time to re-read your posts before you submit them. That gives you time to fix basic errors.

 

[Anna232]

What do you mean by saying that his things "were organised"?

I mean he always put them where they belonged. Is "organized" still wrong?

You need the definite article there.

I don't understand the sentence. What "things" are you referring to and why are you throwing them? *Based on sentence 5, I think you mean "throwing things away". If that's the case, use "about" or "when".

Yes, a lot of different household items or even clothes.

Note my corrections above. In this context, all three words are OK. BrE wouldn't use "trash" and I don't think AmE uses "rubbish".

Do you mean either is OK but "garbage" is preferred in such context?

 

[emsr2d2]

I mean he always put them where they belonged. Is "organized" still wrong?

I'd probably use "well organised" to make it clear that they weren't simply organised in a way that only he found logical.

Yes, I mean "throw things away". I was talking about a lot of different household items or even clothes.

Remember to write in complete sentences.

Do you mean either is they're all OK but "garbage" is preferred in such a context?

I already crossed out "either" because you gave use three options. "Either" is for only two options.
No, at no point did I say that one of them was preferred. I simply told you which words aren't used in a couple of variants. BrE would generally use "rubbish" although I hear "garbage" from some people. AmE would use "garbage" or "trash" but not "rubbish".