The modal verb would

Longman Advanced Learners' grammar says: (p 27/7)

1. Dad would always help us out financially when we were at university, however difficult it was for him.

Is it correct to use 'would' in this context?

Or should it be:

1b. Dad always helped us out financially when we were at university, however difficult it was for him.

Solution 1:

Wikipedia has:

The modal verbs of English are a small class of auxiliary verbs used mostly to express modality (properties such as possibility, obligation, etc.)

We'll leave aside the main verb 'will' (I was willing him to leave , etc). The unmarked, unstressed use of 'will' to form future constructions (Life on the island seems idyllic. But in two days' time, Krakatoa will erupt catastrophically) does not express modality, but is often taken to be a modal usage because of the syntax involved.

AHD plays safe and just uses the hypernymic term 'auxiliary (verb)' here:

would aux.v. Past tense of will2

1. Used to express desire or intent: She said she would meet us at the corner.
2. Used to express a wish: Would that we had gone with you!
3. Used after a statement of desire, request, or advice: I wish you would stay.
4. Used to make a polite request: Would you go with me?
5. Used in the main clause of a conditional statement to express a possibility or likelihood: If I had enough money, I would buy a car. We would have gone to the beach, had the weather been good. See Usage Note at if.
6. Used to express presumption or expectation: That would be Steve at the door.
7. Used to indicate uncertainty: He would seem to be getting better.
8. Used to express repeated or habitual action in the past: Every morning we would walk in the garden.

(How sensible to give 'how-the-word-is-used' rather than synonynous definitions here.)

Sense '8' is the relevant one. Using 'would' gives the repeated / habitual sense that the past tense doesn't (though the 'always' in OP's example also does this).

Another example:

When they first met, they would always have picnics on the beach. [repetition]

Solution 2:

Both are right

"Would" in your first sentence indicates repetition in the past. "He would help us" ~ "He used to help us" ~ "He helped us frequently/regularly"

Compare this with "Dad helped us out financially" - he did it once. But since you have "always" in your sentence, the meaning is changed to something that happened multiple times.

The difference between "always helped us" and "would help us" is that "would help us" leaves the possibility that he regularly helped you but not always. By adding "always" to the "would" phrase "would always help us" is made equivalent to "always helped us"