"Depend on if" means "depend on whether"? [duplicate]

Question

Can I replace "depend on whether" below with "depend on if"? I ask because "whether" can be replaced with "if" some times. ‘I'll see whether she's at home’ same as I'll see if she's at home.

Second language learners’ divergence from target language pragmatic norms | Studies in Second Language Learning and Teaching. Maria Pia Gomez-Laich. Carnegie Mellon University, Pittsburgh .

Although the importance of explicit teaching of pragmatics is well recognized in the literature, learning norms and rules of pragmatics largely depends on learners’ subjectivity. Learners’ convergence or divergence from the L2 pragmatic norms, both consciously and out of awareness, sometimes depends on whether these norms fit their image of self and their L1 cultural identity. Since identity-related conflict can have significant consequences for the acquisition of second language pragmatics, failing to consider the centrality of learners’ identities will produce an inadequate understanding of SLA.

Frontiers | Plasticity, Variability and Age in Second Language Acquisition and Bilingualism | Psychology. David Birdsong, Department of French and Italian, The University of Texas at Austin. Front. Psychol., 12 March 2018 | https://doi.org/10.3389/fpsyg.2018.00081.

That is, the L1 appears to influence pronunciation in the dominant L2, but not the other way around. Perception experiments with a larger sample of Greek–English bilinguals (Antoniou et al., 2012, p. 592) reveal a still more complex pattern of dominance relationships, one that depends on whether the task is categorization or discrimination of voicing: “The results suggest that a bilingual is a single (dominant-language) listener with respect to discrimination, but behaves more like a monolingual of the activated language with respect to discrimination judgments.”

Universal Grammar as a Model of Second Language Learning. Dr. Ahmed Qadoury Al-Khudhairy, Assistant Lecturer, University of Wassit, College of Education, Department of English.

whether a language allows null subject or not

• depends on whether INFL is proper governor (GB)

• depends on morphological uniformity (B)

• depends on whether affixes are generated in the syntax or in the lexicon (MP). See Katamba (1993:56,158-59).

Answer 1

According to Lexico:

If and whether are more or less interchangeable in sentences like I'll see if he left an address and I'll see whether he left an address, although whether is generally regarded as more formal and suitable for written use.

Answer 2

A clause governed by "whether", such as your "whether these norms fit...", can be used as a noun phrase, and can thus be governed by a preposition such as your "on".

But a clause governed by "if" cannot. You may say "Learners’ convergence or divergence ... depend on whether these norms fit...", but it would be ungrammatical to say "Learners’ convergence or divergence ... depend on if these norms fit...".

Answer 3

In broad terms, whether must introduce a single direct alternative state or action (stated or implied).

"Whether it is red or yellow, I will not buy it.” "Whether it is red or not, I will not buy it.”

“Whether it fits [implied = or not] into the hole will depend on the temperature.”

Whether does not introduce a restrictive condition – * I will [not] buy it whether it is red.

If introduces a condition (stated or implied). “I will [not] buy it if it is red." “If it is red, [then] I will [not] buy it."

So, pedantically:

‘I'll see whether she's at home’ = ‘I'll see whether or not she's at home’

I'll see if she's at home. … If she is at home then I will see.