The use of "habit " as an alternative to "used to" [closed]

Are the following structures synonyms? I used to smoke. I was in the habit of smoking. I got into the habit of smoking. I fell into the habit of smoking.

Solution 1:

1. I was in the habit of smoking.
2. I got in(to) the habit of smoking.
3. I fell into the habit of smoking.
4. I used to smoke.

(1-4) are all grammatical, and can all be used to describe the same contexts,
but they don't have the same grammar, and they don't mean the same things.

• (4) is an idiomatic past auxiliary construction used to (pronounced /'yustu/ or /'yustə/),
  which takes an infinitive complement (here the habitual generic infinitive to smoke).

The others are stative and inchoative uses of the idiom Det habit of V-ing,
using a container metaphor, whence in or into:

• (1) is a normal stative Locative construction, auxiliary be + PreoPh; into is not allowed here.

• (2) is an inchoative construction (get is an inchoative for be), using the same metaphor.
  It comments on the initiation of the habit; if it's considered as motion, into is allowed here.

• (3) is a more metaphoric inchoative, adding a gravitational field to the container,
  and requiring a motion construal of the initiation as a fall; into is required here.

As for meanings,

• (4) states that I smoked at a past time and presupposes that I no longer do.

• (1) states that I smoked at a past time and invites the inference that I no longer do.

• (2) states that I started to smoke and continued the habit of smoking at a past time.
  It says nothing about the present state of my habits; this must be determined from context.

• (3) makes the same statement as (2), but construes the initiation of the habit as an error.

As you can see, there are no synonyms here;
indeed, once you look at the fine structure of anything, there are no real synonyms.

Solution 2:

No. All of these constructs could refer to the same thing, but they don't convey the exact same meaning.

"I used to smoke" - perhaps the speaker only smoked occasionally, not habitually, and has since stopped. This sentence doesn't describe a habit, even though it could be referring to one: "I used to smoke two packs a day" would clearly indicate habitual smoking.

"Used to" also works for things we wouldn't describe as habitual: "I used to have a blue car" wouldn't be well replaced with "I was in the habit of having a blue car," for instance.